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Recent advances in high-performance semitransparent perovskite solar cells
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Recent advances in high-performance semitransparent perovskite solar cells Hyeok-Chan Kwon , Jooho Moon PII: DOI: Reference:
S2451-9103(18)30166-2 https://doi.org/10.1016/j.coelec.2018.10.002 COELEC 310
To appear in:
Current Opinion in Electrochemistry
Please cite this article as: Hyeok-Chan Kwon , Jooho Moon , Recent advances in highperformance semitransparent perovskite solar cells, Current Opinion in Electrochemistry (2018), doi: https://doi.org/10.1016/j.coelec.2018.10.002
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Recent advances in high-performance semitransparent perovskite solar cells Hyeok-Chan Kwon and Jooho Moon* Department of Materials Science and Engineering Yonsei University
*Corresponding author: Moon, Jooho ([email protected]) Highlights
Semitransparent perovskite photovoltaics have been developed to realize
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practical applications.
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50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
The recent strategies for structuring semitransparent perovskite layers to achieve high performance are reviewed.
Three categories include ultra-thin absorbers, microstructured absorbers, and nanostructured absorbers.
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Abstract
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Semitransparent perovskite photovoltaics have been developed to realize practical applications, such as windows in buildings/automobiles or the top cells of tandem devices.
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Among the functional layers constituting solar cell devices, fabricating efficient semitransparent light absorbers is one of the key issues for developing semitransparent
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devices. This short review describes the recent strategies for structuring semitransparent
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perovskite layers to achieve high performance in terms of both power conversion efficiency and transmittance. Keywords: Semitransparent perovskite solar cells; ultra-thin absorber layer; microstructured absorber; nanostructured absorber
Introduction Organometal halide perovskite (ABX3, where A is methylammonium or formamidinium, B is Pb or Sn, and X is I, Cl, or Br) solar cells have drawn much attention as inexpensive, highly
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efficient next-generation photovoltaic devices. Since organic-inorganic metal halide perovskite solar cells were first reported in 2009, their power conversion efficiencies (PCEs) have rapidly risen from 3.8% to 23.3% [1]. Superior properties for photovoltaics, such as high absorption coefficients, high carrier mobilities, and long charge diffusion lengths, have
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made perovskite highly promising for next generation photovoltaics [2-4]. In addition, perovskite materials are composed of readily available earth abundant elements and can be fabricated using low-cost solution processing. The typical perovskite solar cell structure is composed of a perovskite absorber inserted between charge transport materials, i.e., an
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electron transport layer (ETL) and a hole transport layer (HTL). The precedent structures of perovskite solar cells involve an infiltrated absorber in a mesoporous TiO2 scaffold [5]. Since that work, thin film planar-type absorbers as well as penetrated absorbers in a mesoporous Al2O3 scaffold have been suggested [6,7].
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Semitransparent solar cells are of great interest for future applications, such as power–
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generating window panels in buildings or automobiles, which would raise the usage ratio of solar energy without occupying additional space [8-11]. For example, building–integrated
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solar cells could lead to the creation of completely self–sustaining, pollution–free buildings. Furthermore, semitransparent solar cells can be stacked in a tandem device architecture in
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which a cell with a higher bandgap is placed atop another with a lower bandgap [12-14]. To
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date, most demonstrated semitransparent solar cells have been based on high-bandgap absorbers, thin polymers, and amorphous silicon absorbers, which result in critical losses in overall efficiency. Perovskite–based absorbers possess outstanding light–absorbing characteristics, and the explicit trade-off between PCE and transparency can be adjusted by varying the thickness of the absorbing layer. Especially, researchers have focused not only on structuring the perovskite layer to endow transparency, but also selecting transparent
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conducting electrodes [15-20] or electron/hole transport layers [21-25] for enhancing the performance of semitransparent perovskite solar cells, as schematically illustrated in Figure 1. The purpose of this short review is to highlight some of these very recent developments on semitransparent perovskite solar cells. As we do not aim to be extensive in
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this review, the emphasis will be on the structuring of the perovskite absorber layer. Specifically, we will cover three areas, ultra-thin absorbers, microstructured absorbers, and nanostructured absorbers, as illustrated in Figure 2. We will not cover other approaches for controlling transparent conducting electrodes and/or electron/hole transport layers in this
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review, however, some important results are briefly summarized in Table 1, and the reader is referred to other relevant recent reviews [26-29].
Ultra-thin absorber-based semitransparent perovskite solar cells Since thin film perovskite-based planar structure solar cells have already been successfully
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demonstrated, simply decreasing the perovskite absorber thickness would be an effective
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strategy to provide transparency to full devices (Figure 2a). The ultra-thin absorber could transmit a certain portion of visible light when the thickness is less than the penetration depth.
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To accomplish ultra-thin absorber, spin-coating with a low concentrated solution or using coevaporation technique was suggested. The antisolvent method was adopted for fabricating
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ultra-thin semitransparent perovskites with dense and uniform perovskite layers by fast
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crystallization. For example, Quiroz et al. used a solvent-solvent extraction method, in which the perovskite precursor spin-coated substrate was dipped into a toluene solvent, enabling the formation of a uniform and ultra-thin perovskite layer [30]. A gas-assisted spin-coating process for uniform perovskite films has been also reported, and Gaspera et al. achieved continuous 107 nm thick CH3NH3PbI3 thin films using this techniques, which showed a PCE of 8.1% and average visible transmittance (AVT) of 19% [31]. Aside from one-step spincoating methods, two step spin-coating methods involving sequential spin-coatings of two
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different precursor solutions were also presented. Bag et al. used thiourea vapor treatment on a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer followed by a two-step spin-coating method for better coverage and uniformity of an ultra-thin perovskite layer, achieving a PCE of 8.2% and AVT of 34% [32].
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Vacuum-based process have also been suggested for realizing ultra-thin films [33]. Uniform perovskite thin films can be achieved via an evaporation method, simultaneously depositing the perovskite precursors on the substrate. Roldan–Carmona et al. fabricated a semitransparent perovskite absorber by employing an evaporated 280 nm thick perovskite
al. reported centimeter–scale (5
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absorber layer, which exhibited a PCE of 6.4% and AVT of 30% [34]. Additionally, Ono et 5 cm2) evaporated thin films of CH3NH3PbI3 with
thicknesses of 135 nm for semitransparent solar cells, achieving PCEs of 9.9% [35]. Kim et
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al. also proposed a short-spinning and vacuum drying method based on a vacuum assisted process, revealing ultra-smooth and low-scattering ultrathin semitransparent films [36].
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Facile one-step spin-coating processes using additives in a perovskite precursor solution have also been developed to simplify the fabrication process or improve long-term
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stability. Heo et al. added a HI additive in the perovskite precursor solution to achieve a
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uniform and ultra-thin film in a one-step spin-coating method, demonstrating a PCE of 12.55% and AVT of 17.3% [37]. Guo et al. also suggested an ultra-thin semitransparent layer
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using a polyvinylpyrrolidone additive, which showed an efficiently increase in its open circuit voltage (VOC) value induced by stabilized perovskite cubic nanocrystals [38]. Zhang et al. used a perovskite precursor solution containing a poly(vinylidenefluoride-cohexafluoropropylene) additive to a obtain smooth and large grain-sized perovskite film using a one-step spin-coating method and controlling the crystal growth rate [39]. Microstructured absorber-based semitransparent perovskite solar cells
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Microstructured perovskite absorbers have been used to achieve semitransparency by making fully transparent regions where perovskite was not present, while having the advantage of wavelength-selective light transmission, even demonstrating neutral colored semitransparent solar cells (Figure 2b). This structure could be fabricated using dewetting strategies or micro-
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scale template. Eperon et al. first introduced microstructured and neutral colored perovskitebased semitransparent solar cells by fabricating a perovskite island structure using a dewetting phenomenon, which showed a PCE of 3.5% and AVT of ~30% [40]. The same group also reported an improved efficiency of 5.2% and AVT of 28% by replacing the
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perovskite material, CH3NH3PbI3-XClX, with HC(NH2)2PbI3, which also showed an increased VOC and current density (JSC) [41]. This structure had the advantage of being able to produce neutral-colored semitransparent devices by controlling the perovskite region, to completely absorb visible light, and void region, to completely transmit visible light, while the ultra-thin
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film showed a red-shifted color. However, the aforementioned structure demonstrated a
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relatively low VOC value due to the shunting path between the electron transport layer and hole transport layer in the region where there was no perovskite phase. To avoid the shunting
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path, Hörantner et al. and Heo et al. used the trichloro(octadecyl)silane molecule and a polystyrene (PS) passivation interlayer, respectively, for blocking the shunting path [42,43].
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This approach can reduce recombination effectively by blocking the contact between the
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electron and hole transport layers, enhancing the VOC value. Besides randomly formed semitransparent perovskite microstructures, ordered
microstructures have also been suggested. One example is the PS-derived microstructure template technique that leads to formation of a uniform microstructured perovskite layer. Hörantner et al. and Zhang et al. fabricated microstructured perovskite layers using spincoating on micro-pore patterned oxide structures fabricated by filling the gaps of closely packed PS microspheres with an oxide precursor solution, followed by removal of the PS
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beads by sintering the film [44,45]. An ordered macroporous perovskite film-based semitransparent solar cell was also investigated by Chen et al., fabricated by removing the PS monolayer after filling perovskite into the pores, showing a promising efficiency of 11.7% with an active layer AVT of 36.5% [46]. Another approach is the fabrication of mesh-
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structured perovskite, providing transparency through the open regions of the mesh. Aharon et al. and Rahmany et al. fabricated mesh-patterned perovskite layers using the direct meshassisted assembly deposition method, exhibiting PCE of 5% and AVT of 20% [47,48]. Nanostructured absorber-based semitransparent perovskite solar cells
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To increase the performance of semitransparent solar cell devices, strategies for maximizing the PCE at a certain whole-device transmittance are required. One of the methods for achieving this concept is to structure the semitransparent perovskite absorber at the nanometer scale for better charge collection efficiency by increasing the charge
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transport/extraction rate through 1-D structure or by blending the perovskite absorber and the
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charge transport material (Figure 2c). A perovskite-phenyl-C61-butyric acid methyl ester (PCBM) hybrid structure in which PCBM penetrated into the perovskite grain boundaries
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was reported for better charge extraction through the increased PCBM/perovskite interfaces
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[49]. Xiao et al. also incorporated mesoporous TiO2 in the perovskite-PCBM hybrid structure, showing a PCE of 8.21% and AVT of 23% [50]. A blended structure with an oxide material
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based on a perovskite-NiO composite structure to enhance the hole extraction rate was also investigated, revealing a high PCE of 10.06% and AVT of 27% [51]. A well-ordered perovskite nanostructure for efficient semitransparent solar cell was
also suggested. Vertically aligned nanopillar-type perovskite was fabricated by employing an anodized aluminium oxide (AAO) template as an insulating scaffold layer [52,53]. This concept was based on the combined advantages of the enhanced charge transport/extraction
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properties of 1-D structures and increased transmittance due to vertically arrayed nanopillar absorber structures, allowing for facile charge transport and reduced reflectance. This structure exhibited exceptional performance with PCEs of 9.6% and a whole-device AVT of 33.4%, with significantly reduced haziness. Also, the nanopillar-based solar cell showed less
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J-V hysteresis than that of the planar structure, induced by ion diffusion inhibition due to the decreased defect density. Conclusions and outlook
Significant progress in semitransparent perovskite solar cells has been achieved. Various
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strategies using conventional methods or unique technologies for providing transparency to light absorber have been demonstrated, revealing high efficiencies of 10% as well as average visible light transparencies of 30%. An overview of semitransparent perovskite solar cells
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developed for the structuring of light absorbers is summarized in Figure 3 and Table 1. This summary clearly indicates that the performance of semitransparent perovskite solar cell
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technology has reached a mature stage. However, to open the markets of solar windows based on these perovskite absorbers, other issues, such as degradation of perovskite due to moisture
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or constant illumination, high production costs by use of vacuum deposited top/bottom
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transparent electrodes, and deteriorated performance when scaling up into large area devices, should be also well addressed prior to their full exploitation.
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Firstly, since long-term stability of solar cells is a prerequisite for commercialization,
the various efforts to achieve better stability have been pursued. In the case of moisture stability, encapsulating the device using an atomic layer deposition technique or forming a superhydrophobic coating on the upper layer of the perovskite could be candidates for preventing moisture penetration. Perovskite absorber degradation induced by halide ion migration is another issue to be resolved, and this could be improved by fabricating high-
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quality perovskite crystal grains or mixing a cation or halide of perovskite, interrupting the halide ion diffusion, all of which have been successfully investigated for opaque perovskite solar cells. In addition, efficiently functioning transparent electrodes with low-cost materials and
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an inexpensive fabrication process should be developed for reducing manufacturing costs while maintaining high performance of semitransparent solar cells. Although low cost transparent electrodes, such as metal nanowires or carbon-based electrodes, for semitransparent solar cells have been reported, whole devices based on inexpensive
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electrodes for both the top and bottom sides have been rarely reported. The main hurdle for their realization is that the perovskite phase easily dissolves in various polar solvents and decomposes when annealed over 100 ℃, impeding post-annealing. Therefore, research
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focused on adopting or finding low-cost transparent electrodes for both sides without damaging the perovskite absorber is in high demand.
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Finally, the primary issue for solution-processable perovskite scale-up production is
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the control of the uniform absorber film formation over large areas, overcoming the complex growth behavior of perovskite films. Moreover, a semitransparent absorber should be ultra-
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thin (below 100 nm) or even involve micro/nanoscale structuring. These requirements pose a great hurdle in large area absorber fabrication compared to conventional opaque solar cell
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fabrication. Scale-up technology including roll-to-roll fabrication for opaque perovskite solar cells and modules has been recently developed close to the commercialization level. Similar approaches should be carried out for exploiting the potential promising applications based on semitransparent perovskite solar cells. Conflict of interest
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None exists for this review. Acknowledgments This work was supported by a grant from the National Research Foundation of Korea funded by the Korean government (MISP) (No. 2012R1A3A2026417). This research was also
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partially supported by the Graduate School of YONSEI University Research Scholarship Grants in 2018. References and recommended reading
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Papers of particular interest, published within the period of review, have been highlighted as: •Paper of special interest. ••Paper of outstanding interest.
1. Kojima A, Teshima K, Shirai Y, Miyasaka T: Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J Am Chem Soc 2009, 131:6050-6051.
M
•• First report of using organometal halide perovskite as a solar cell.
2. Im JH, Lee CR, Lee JW, Park SW, Park NG: 6.5% efficient perovskite quantum-dot-
ED
sensitized solar cell. Nanoscale 2011, 3:4088-4093. 3. Edri E, Kirmayer S, Henning A, Mukhopadhyay S, Gartsman K, Rosenwaks Y, Hodes G, Cahen D: Why Lead Methylammonium Tri-Iodide Perovskite-Based Solar Cells
PT
Require a Mesoporous Electron Transporting Scaffold (but Not Necessarily a Hole Conductor). Nano Lett 2014, 14:1000-1004.
CE
4. Stranks SD, Eperon GE, Grancini G, Menelaou C, Alcocer MJP, Leijtens T, Herz LM, Petrozza A, Snaith HJ: Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in
AC
an Organometal Trihalide Perovskite Absorber. Science 2013, 342:341-344.
5. Kim HS, Lee CR, Im JH, Lee KB, Moehl T, Marchioro A, Moon SJ, Humphry-Baker R, Yum JH, Moser JE, et al.: Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%. Sci Rep 2012, 2:591. •• First demonstration of a solid hole transport layer, showing higher efficiency and stability of the perovskite solar cell. 6. Xing GC, Mathews N, Sun SY, Lim SS, Lam YM, Gratzel M, Mhaisalkar S, Sum TC:
9
ACCEPTED MANUSCRIPT
Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH3NH3PbI3. Science 2013, 342:344-347. •• First demonstration of a solid hole transport layer, showing higher efficiency and stability of the perovskite solar cell. 7. Lee MM, Teuscher J, Miyasaka T, Murakami TN, Snaith HJ: Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science 2012,
CR IP T
338:643-647.
8. Norton B, Eames PC, Mallick TK, Huang MJ, McCormack SJ, Mondol JD, Yohanis YG: Enhancing the performance of building integrated photovoltaics. Sol Energy 2011, 85:1629-1664.
9. Vats K, Tiwari GN: Energy and exergy analysis of a building integrated
AN US
semitransparent photovoltaic thermal (BISPVT) system. Appl Energy 2012, 96:409416.
10. Xue QF, Xia RX, Brabec CJ, Yip HL: Recent advances in semi-transparent polymer and perovskite solar cells for power generating window applications. Energy Environ Sci 2018, 11:1688-1709.
Adv Mater 2017, 29:1700192.
M
11. Tai QD, Yan F: Emerging Semitransparent Solar Cells: Materials and Device Design.
ED
12. Beiley ZM, McGehee MD: Modeling low cost hybrid tandem photovoltaics with the potential for efficiencies exceeding 20%. Energy Environ Sci 2012, 5:9173-9179.
PT
13. Chen CC, Dou LT, Gao J, Chang WH, Li G, Yang Y: High-performance semitransparent polymer solar cells possessing tandem structures. Energy Environ Sci
CE
2013, 6:2714-2720.
14. Chen B, Zheng XP, Bai Y, Padture NP, Huang JS: Progress in Tandem Solar Cells
AC
Based on Hybrid Organic-Inorganic Perovskites. Adv Energy Mater 2017, 7:1602400. 15. Quiroz COR, Bronnbauer C, Levchuk I, Hou Y, Brabec CJ, Forberich K: Coloring Semitransparent Perovskite Solar Cells via Dielectric Mirrors. ACS Nano 2016, 10:5104-5112.
16. You P, Liu ZK, Tai QD, Liu SH, Yan F: Efficient Semitransparent Perovskite Solar Cells with Graphene Electrodes. Adv Mater 2015, 27:3632-3638. 17. Guo F, Azimi H, Hou Y, Przybilla T, Hu MY, Bronnbauer C, Langner S, Spiecker E, Forberich K, Brabec CJ: High-performance semitransparent perovskite solar cells with solution-processed silver nanowires as top electrodes. Nanoscale 2015, 7:1642-
10
ACCEPTED MANUSCRIPT
1649. 18. Zhao J, Brinkmann KO, Hu T, Pourdavoud N, Becker T, Gahlmann T, Heiderhoff R, Polywka A, Gorrn P, Chen Y, et al.: Self-Encapsulating Thermostable and AirResilient Semitransparent Perovskite Solar Cells. Adv Energy Mater 2017, 7:1602599. 19. Li FR, Xu Y, Chen W, Xie SH, Li JY: Nanotube enhanced carbon grids as top electrodes for fully printable mesoscopic semitransparent perovskite solar cells. J
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Mater Chem A 2017, 5:10374-10379.
20. Fang YS, Wu ZC, Li J, Jiang FY, Zhang K, Zhang YL, Zhou YH, Zhou J, Hu B: HighPerformance Hazy Silver Nanowire Transparent Electrodes through Diameter Tailoring for Semitransparent Photovoltaics. Adv Func Mater 2018, 28:1705409.
21. Jung JW, Chueh CC, Jen AKY: High-Performance Semitransparent Perovskite Solar
AN US
Cells with 10% Power Conversion Efficiency and 25% Average Visible Transmittance Based on Transparent CuSCN as the Hole-Transporting Material. Adv Energy Mater 2015, 5:1500486.
22. Fu F, Feurer T, Weiss TP, Pisoni S, Avancini E, Andres C, Buecheler S, Tiwari AN: Higheffciency inverted semi-transparent planar perovskite solar cells in substrate
M
configuration. Nat Energy 2017, 2:16190.
23. Chang CY, Lee KT, Huang WK, Siao HY, Chang YC: High-Performance, Air-Stable,
ED
Low-Temperature Processed Semitransparent Perovskite Solar Cells Enabled by Atomic Layer Deposition. Chem Mater 2015, 27:5122-5130.
PT
24. Chang CY, Chang YC, Huang WK, Lee KT, Cho AC, Hsu CC: Enhanced Performance and Stability of Semitransparent Perovskite Solar Cells Using Solution-Processed
CE
Thiol-Functionalized Cationic Surfactant as Cathode Buffer Layer. Chem Mater 2015, 27:7119-7127.
AC
25. Xue QF, Bai Y, Liu MY, Xia RX, Hu ZC, Chen ZM, Jiang XF, Huang F, Yang SH, Matsuo Y, et al.: Dual Interfacial Modifications Enable High Performance Semitransparent Perovskite Solar Cells with Large Open Circuit Voltage and Fill Factor. Adv Energy Mater 2017, 7:1770047.
26. Traverse CJ, Pandey R, Barr MC, Lunt RR: Emergence of highly transparent photovoltaics for distributed applications. Nat Energy 2017, 2:849-860. •• Comprehensive review on transparent or semitransparent photovoltaics for real application. 27. Lee K-T, Guo L, Park H: Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells. Molecules 2016, 21:475.
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28. Shin DH, Jang CW, Lee HS, Seo SW, Choi SH: Semitransparent Flexible Organic Solar Cells Employing Doped-Graphene Layers as Anode and Cathode Electrodes. ACS Appl Mater Interfaces 2018, 10:3596-3601. 29. Sun J, Jasieniak JJ: Semi-transparent solar cells. J Phys D: Appl Phys 2017, 50:093001. 30. Quiroz COR, Levchuk L, Bronnbauer C, Salvador M, Forberich K, Heumuller T, Hou Y, Schweizer P, Spiecker E, Brabec CJ: Pushing efficiency limits for semitransparent
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perovskite solar cells. J Mater Chem A 2015, 3:24071-24081.
31. Della Gaspera E, Peng Y, Hou QC, Spiccia L, Bach U, Jasieniak JJ, Cheng YB: Ultrathin high efficiency semitransparent perovskite solar cells. Nano Energy 2015, 13:249-257.
32. Bag S, Durstock MF: Efficient semi-transparent planar perovskite solar cells using a
AN US
'molecular glue'. Nano Energy 2016, 30:542-548.
33. Ono LK, Leyden MR, Wang SH, Qi YB: Organometal halide perovskite thin films and solar cells by vapor deposition. J Mater Chem A 2016, 4:6693-6713. 34. Roldan-Carmona C, Malinkiewicz O, Betancur R, Longo G, Momblona C, Jaramillo F, Camacho L, Bolink HJ: High efficiency single-junction semitransparent perovskite
M
solar cells. Energy Environ Sci 2014, 7:2968-2973.
35. Ono LK, Wang SH, Kato Y, Raga SR, Qi YB: Fabrication of semi-transparent
ED
perovskite films with centimeter-scale superior uniformity by the hybrid deposition method. Energy Environ Sci 2014, 7:3989-3993.
PT
• First report of semitransparent perovskite solar cell using the evaporation method. 36. Kim GM, Tatsuma T: Semitransparent Solar Cells with Ultrasmooth and Low-
CE
Scattering Perovskite Thin Films. J Phys Chem C 2016, 120:28933-28938. 37. Heo JH, Han HJ, Lee M, Song M, Kim DH, Im SH: Stable semi-transparent
AC
CH3NH3PbI3 planar sandwich solar cells. Energy Environ Sci 2015, 8:2922-2927. 38. Guo YL, Shoyama K, Sato W, Nakamura E: Polymer Stabilization of Lead(II) Perovskite Cubic Nanocrystals for Semitransparent Solar Cells. Adv Energy Mater 2016, 6:1502317.
39. Zhang S, Lu YT, Lin BC, Zhu YY, Zhang KZ, Yuan NY, Ding JN, Fang BJ: PVDF-HFP additive for visible-light-semitransparent perovskite films yielding enhanced photovoltaic performance. Sol Energy Mater Sol Cells 2017, 170:178-186. 40. Eperon GE, Burlakov VM, Goriely A, Snaith HJ: Neutral Color Semitransparent Microstructured Perovskite Solar Cells. ACS Nano 2014, 8:591-598.
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ACCEPTED MANUSCRIPT
•• This work shows the island structured perovskite based neutral color semitransparent solar cell fot the first time. 41. Eperon GE, Bryant D, Troughton J, Stranks SD, Johnston MB, Watson T, Worsley DA, Snaith HJ: Efficient, Semitransparent Neutral-Colored Solar Cells Based on Microstructured Formamidinium Lead Trihalide Perovskite. J Phys Chem Lett 2015, 6:129-138.
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42. Horantner MT, Nayak PK, Mukhopadhyay S, Wojciechowski K, Beck C, McMeekin D, Kamino B, Eperon GE, Snaith HJ: Shunt-Blocking Layers for Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2016, 3:1500837.
43. Heo JH, Jang MH, Lee MH, Han HJ, Kang MG, Lee ML, Im SH: Efficiency enhancement of semi-transparent sandwich type CH3NH3PbI3 perovskite solar cells
AN US
with island morphology perovskite film by introduction of polystyrene passivation layer. J Mater Chem A 2016, 4:16324-16329.
44. Horantner MT, Zhang W, Saliba M, Wojciechowski K, Snaith HJ: Templated microstructural growth of perovskite thin films via colloidal monolayer lithography. Energy Environ Sci 2015, 8:2041-2047.
M
45. Zhang LJ, Horantner MT, Zhang W, Yan QF, Snaith HJ: Near-neutral-colored semitransparent perovskite films using a combination of colloidal self-assembly and
ED
plasma etching. Sol Energy Mater Sol Cells 2017, 160:193-202. 46. Chen BX, Rao HS, Chen HY, Li WG, Kuang DB, Su CY: Ordered macroporous
PT
CH3NH3PbI3 perovskite semitransparent film for high-performance solar cells. J Mater Chem A 2016, 4:15662-15669.
CE
47. Aharon S, Layani M, Cohen BE, Shukrun E, Magdassi S, Etgar L: Self-Assembly of Perovskite for Fabrication of Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2015, 2:1500118.
AC
• A unique structure of perovskite mesh is investigated for semitransparent solar cell. 48. Rahmany S, Layani M, Magdassi S, Etgar L: Fully functional semi-transparent perovskite solar cell fabricated in ambient air. Sustain Energy Fuels 2017, 1:21202127. 49. Li C, Sleppy J, Dhasmana N, Soliman M, Tetard L, Thomas J: A PCBM-assisted perovskite growth process to fabricate high efficiency semitransparent solar cells. J Mater Chem A 2016, 4:11648-11655. 50. Xiao S, Chen HN, Jiang FY, Bai Y, Zhu ZL, Zhang T, Zheng XL, Qian GY, Hu C, Zhou
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YH, et al.: Hierarchical Dual-Scaffolds Enhance Charge Separation and Collection for High Efficiency Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2016, 3:1600484. 51. Wang YS, Mahmoudi T, Yang HY, Bhat KS, Yoo JY, Hahn YB: Fully-ambient-processed mesoscopic semitransparent perovskite solar cells by islands-structure-MAPbI(3x)Cl(x)-NiO
composite and Al2O3/NiO interface engineering. Nano Energy 2018, 49:59-
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66.
52. Kwon HC, Kim A, Lee H, Lee D, Jeong S, Moon J: Parallelized Nanopillar Perovskites for Semitransparent Solar Cells Using an Anodized Aluminum Oxide Scaffold. Adv Energy Mater 2016, 6:1601055.
•• Vertically aligned 1-D perovskite based semitransparent solar cell was demonstrated for
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the first time.
53. Kwon HC, Yang W, Lee D, Ahn J, Lee E, Ma S, Kim K, Yun SC, Moon J: Investigating Recombination and Charge Carrier Dynamics in a One-Dimensional Nanopillared
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CE
PT
ED
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Perovskite Absorber. ACS Nano 2018, 12:4233-4245.
Figure 1. Device structure and a photography of semitransparent perovskite solar cell, and
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various research strategies for enhancing performance.
Figure 2. Fabrication strategies and optical/electrical effects for three different semitransparent perovskite absorber structures: (a) ultra-thin absorber, (b) microstructured
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absorber, and (c) nanostructured absorber.
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Figure 3. Whole-device AVT versus PCE plot of semitransparent perovskite solar cells whose themes are focused on the structuring of the light absorber.
Table 1. Summary of semitransparent perovskite solar cells with various light absorber
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structures.
Fabrication method
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Perovskite absorber type
Anti-solvent dipping Gas-assisted spincoating
Two-step spin-coating Evaporation
Thin film Evaporation Vacuum assisted drying HI additive PVP additive
Device structure Ag nanowire/ZnO/PCBM/ CH3NH3PbI3-XClX/PEDOT:PSS/ITO MoO3/Au/MoO3/spiro-OMeTAD/ CH3NH3PbI3/c-TiO2/FTO Ag/AUHa/C60/PCBM/CH3NH3PbI3/ PEDOT:PSS/ITO LiF/Au/PCBM60/CH3NH3PbI3/ polyTPDb/PEDOT:PSS/ITO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ c-TiO2/FTO MoO3/Ag/BCP/PCBM/CH3NH3PbI3/ PEDOT:PSS/ITO ITO/PEDOT:PSS/PTAAc/ CH3NH3PbI3/c-TiO2/FTO Au/polyethylenimine/PCBM/CYTOPd/ CH3NH3PbI3-XClX/PEDOT:PSS/ITO
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Average visible light transmittance
Power conversion Reference efficiency
28-46%
3.55-8.12%
30
7-31%
5.3-13.6%
31
12-47%
4.5-13.3%
32
10-35.4%
3.39-7.73%
34
-
6.3-9.9%
35
-
6.87-10.66%
36
12.6-15.9%
6.3-17.3%
37
34%
5.36%
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Dewetting (Island) Dewetting (Island) Dewetting (Island) Dewetting (Island)
Nanostructure
Micro-pore oxide template Micro-pore oxide template Macroporous perovskite Mesh-assisted assembly (grid) Mesh-assisted assembly (grid) PCBM-assisted perovskite growth (hybrid) PCBM-assisted perovskite growth (hybrid)
Au/spiro-OMeTAD/CH3NH3PbI3 grid/ meso-TiO2/c-TiO2/FTO
Mesoporous scaffold Anodized aluminum oxide scaffold (nanopillar)
MoO3/Au/MoO3/spiro-OMeTAD/ CH3NH3PbI3 grid/meso-Al2O3/ meso-TiO2/c-TiO2/FTO Au/PCBM/CH3NH3PbI3-PEDOT:PSS hybrid/ PEDOT:PSS/ITO PEDOT:PSS/spiro-OMeTAD/ CH3NH3PbI3-PEDOT:PSS hybrid/ meso-TiO2/c-TiO2/FTO Au/spiro-OMeTAD/ CH3NH3PbI3-XClX-NiO composite/ meso-Al2O3/meso-TiO2/c-TiO2/FTO
32.40%
8.80%
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7-30%
3.5-8%
40
28%
5.20%
41
38%
6.10%
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20.90%
10.60%
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9.5%, 4.5%
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10.30%
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28%, 37% (without top electrode) 38% (only light absorb layer) 36.5% (only light absorb layer) 19-64% (without top electrode and spiro-OMeTAD)
11.70%
46
0.83-4.98%
47
26%
5.50%
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3%, 18%
9.1%, 12.2%
49
23%
8%
50
27%
10.06%
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33.4-46.0%
5.7-9.6%
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Microstructure
Au/spiro-OMeTAD/CH3NH3PbI3/ c-TiO2/FTO Au/spiro-OMeTAD/CH3NH3PbI3-XClX/ c-TiO2/FTO Au/spiro-OMeTAD/HC(NH2)2PbI3/ c-TiO2/FTO Ni grid/spiro-OMeTAD/CH3NH3PbI3/ octadecyl-siloxane/c-TiO2/FTO ITO/PEDOT:PSS/PTAA/CH3NH3PbI3/ PS/c-TiO2/FTO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ SiO2 honeycomb scaffold/c-TiO2/FTO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ SiO2 honeycomb scaffold/c-TiO2/FTO Au/spiro-OMeTAD/CH3NH3PbI3/ c-TiO2/FTO
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PVDF-HFPe additive
ITO/MoOX/spiro-OMeTAD/ CH3NH3PbI3-XClX+AAO/c-TiO2/FTO
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CE
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a: 11-amino-1-undecanethiol hydrochloride, b: poly[N,N0-bis(4-butylphenyl)-N,N0-bis(phenyl)benzidine], c: Poly[bis(4phenyl)(2,4,6-trimethylphenyl)amine], d: commercial fluorous polymer, e: poly(vinylidenefluoride-co-hexafluoropropylene)
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Recent advances in high-performance semitransparent perovskite solar cells Hyeok-Chan Kwon , Jooho Moon PII: DOI: Reference:
S2451-9103(18)30166-2 https://doi.org/10.1016/j.coelec.2018.10.002 COELEC 310
To appear in:
Current Opinion in Electrochemistry
Please cite this article as: Hyeok-Chan Kwon , Jooho Moon , Recent advances in highperformance semitransparent perovskite solar cells, Current Opinion in Electrochemistry (2018), doi: https://doi.org/10.1016/j.coelec.2018.10.002
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Recent advances in high-performance semitransparent perovskite solar cells Hyeok-Chan Kwon and Jooho Moon* Department of Materials Science and Engineering Yonsei University
*Corresponding author: Moon, Jooho ([email protected]) Highlights
Semitransparent perovskite photovoltaics have been developed to realize
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practical applications.
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50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
The recent strategies for structuring semitransparent perovskite layers to achieve high performance are reviewed.
Three categories include ultra-thin absorbers, microstructured absorbers, and nanostructured absorbers.
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Abstract
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Semitransparent perovskite photovoltaics have been developed to realize practical applications, such as windows in buildings/automobiles or the top cells of tandem devices.
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Among the functional layers constituting solar cell devices, fabricating efficient semitransparent light absorbers is one of the key issues for developing semitransparent
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devices. This short review describes the recent strategies for structuring semitransparent
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perovskite layers to achieve high performance in terms of both power conversion efficiency and transmittance. Keywords: Semitransparent perovskite solar cells; ultra-thin absorber layer; microstructured absorber; nanostructured absorber
Introduction Organometal halide perovskite (ABX3, where A is methylammonium or formamidinium, B is Pb or Sn, and X is I, Cl, or Br) solar cells have drawn much attention as inexpensive, highly
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efficient next-generation photovoltaic devices. Since organic-inorganic metal halide perovskite solar cells were first reported in 2009, their power conversion efficiencies (PCEs) have rapidly risen from 3.8% to 23.3% [1]. Superior properties for photovoltaics, such as high absorption coefficients, high carrier mobilities, and long charge diffusion lengths, have
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made perovskite highly promising for next generation photovoltaics [2-4]. In addition, perovskite materials are composed of readily available earth abundant elements and can be fabricated using low-cost solution processing. The typical perovskite solar cell structure is composed of a perovskite absorber inserted between charge transport materials, i.e., an
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electron transport layer (ETL) and a hole transport layer (HTL). The precedent structures of perovskite solar cells involve an infiltrated absorber in a mesoporous TiO2 scaffold [5]. Since that work, thin film planar-type absorbers as well as penetrated absorbers in a mesoporous Al2O3 scaffold have been suggested [6,7].
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Semitransparent solar cells are of great interest for future applications, such as power–
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generating window panels in buildings or automobiles, which would raise the usage ratio of solar energy without occupying additional space [8-11]. For example, building–integrated
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solar cells could lead to the creation of completely self–sustaining, pollution–free buildings. Furthermore, semitransparent solar cells can be stacked in a tandem device architecture in
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which a cell with a higher bandgap is placed atop another with a lower bandgap [12-14]. To
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date, most demonstrated semitransparent solar cells have been based on high-bandgap absorbers, thin polymers, and amorphous silicon absorbers, which result in critical losses in overall efficiency. Perovskite–based absorbers possess outstanding light–absorbing characteristics, and the explicit trade-off between PCE and transparency can be adjusted by varying the thickness of the absorbing layer. Especially, researchers have focused not only on structuring the perovskite layer to endow transparency, but also selecting transparent
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conducting electrodes [15-20] or electron/hole transport layers [21-25] for enhancing the performance of semitransparent perovskite solar cells, as schematically illustrated in Figure 1. The purpose of this short review is to highlight some of these very recent developments on semitransparent perovskite solar cells. As we do not aim to be extensive in
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this review, the emphasis will be on the structuring of the perovskite absorber layer. Specifically, we will cover three areas, ultra-thin absorbers, microstructured absorbers, and nanostructured absorbers, as illustrated in Figure 2. We will not cover other approaches for controlling transparent conducting electrodes and/or electron/hole transport layers in this
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review, however, some important results are briefly summarized in Table 1, and the reader is referred to other relevant recent reviews [26-29].
Ultra-thin absorber-based semitransparent perovskite solar cells Since thin film perovskite-based planar structure solar cells have already been successfully
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demonstrated, simply decreasing the perovskite absorber thickness would be an effective
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strategy to provide transparency to full devices (Figure 2a). The ultra-thin absorber could transmit a certain portion of visible light when the thickness is less than the penetration depth.
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To accomplish ultra-thin absorber, spin-coating with a low concentrated solution or using coevaporation technique was suggested. The antisolvent method was adopted for fabricating
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ultra-thin semitransparent perovskites with dense and uniform perovskite layers by fast
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crystallization. For example, Quiroz et al. used a solvent-solvent extraction method, in which the perovskite precursor spin-coated substrate was dipped into a toluene solvent, enabling the formation of a uniform and ultra-thin perovskite layer [30]. A gas-assisted spin-coating process for uniform perovskite films has been also reported, and Gaspera et al. achieved continuous 107 nm thick CH3NH3PbI3 thin films using this techniques, which showed a PCE of 8.1% and average visible transmittance (AVT) of 19% [31]. Aside from one-step spincoating methods, two step spin-coating methods involving sequential spin-coatings of two
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different precursor solutions were also presented. Bag et al. used thiourea vapor treatment on a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer followed by a two-step spin-coating method for better coverage and uniformity of an ultra-thin perovskite layer, achieving a PCE of 8.2% and AVT of 34% [32].
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Vacuum-based process have also been suggested for realizing ultra-thin films [33]. Uniform perovskite thin films can be achieved via an evaporation method, simultaneously depositing the perovskite precursors on the substrate. Roldan–Carmona et al. fabricated a semitransparent perovskite absorber by employing an evaporated 280 nm thick perovskite
al. reported centimeter–scale (5
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absorber layer, which exhibited a PCE of 6.4% and AVT of 30% [34]. Additionally, Ono et 5 cm2) evaporated thin films of CH3NH3PbI3 with
thicknesses of 135 nm for semitransparent solar cells, achieving PCEs of 9.9% [35]. Kim et
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al. also proposed a short-spinning and vacuum drying method based on a vacuum assisted process, revealing ultra-smooth and low-scattering ultrathin semitransparent films [36].
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Facile one-step spin-coating processes using additives in a perovskite precursor solution have also been developed to simplify the fabrication process or improve long-term
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stability. Heo et al. added a HI additive in the perovskite precursor solution to achieve a
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uniform and ultra-thin film in a one-step spin-coating method, demonstrating a PCE of 12.55% and AVT of 17.3% [37]. Guo et al. also suggested an ultra-thin semitransparent layer
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using a polyvinylpyrrolidone additive, which showed an efficiently increase in its open circuit voltage (VOC) value induced by stabilized perovskite cubic nanocrystals [38]. Zhang et al. used a perovskite precursor solution containing a poly(vinylidenefluoride-cohexafluoropropylene) additive to a obtain smooth and large grain-sized perovskite film using a one-step spin-coating method and controlling the crystal growth rate [39]. Microstructured absorber-based semitransparent perovskite solar cells
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Microstructured perovskite absorbers have been used to achieve semitransparency by making fully transparent regions where perovskite was not present, while having the advantage of wavelength-selective light transmission, even demonstrating neutral colored semitransparent solar cells (Figure 2b). This structure could be fabricated using dewetting strategies or micro-
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scale template. Eperon et al. first introduced microstructured and neutral colored perovskitebased semitransparent solar cells by fabricating a perovskite island structure using a dewetting phenomenon, which showed a PCE of 3.5% and AVT of ~30% [40]. The same group also reported an improved efficiency of 5.2% and AVT of 28% by replacing the
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perovskite material, CH3NH3PbI3-XClX, with HC(NH2)2PbI3, which also showed an increased VOC and current density (JSC) [41]. This structure had the advantage of being able to produce neutral-colored semitransparent devices by controlling the perovskite region, to completely absorb visible light, and void region, to completely transmit visible light, while the ultra-thin
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film showed a red-shifted color. However, the aforementioned structure demonstrated a
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relatively low VOC value due to the shunting path between the electron transport layer and hole transport layer in the region where there was no perovskite phase. To avoid the shunting
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path, Hörantner et al. and Heo et al. used the trichloro(octadecyl)silane molecule and a polystyrene (PS) passivation interlayer, respectively, for blocking the shunting path [42,43].
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This approach can reduce recombination effectively by blocking the contact between the
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electron and hole transport layers, enhancing the VOC value. Besides randomly formed semitransparent perovskite microstructures, ordered
microstructures have also been suggested. One example is the PS-derived microstructure template technique that leads to formation of a uniform microstructured perovskite layer. Hörantner et al. and Zhang et al. fabricated microstructured perovskite layers using spincoating on micro-pore patterned oxide structures fabricated by filling the gaps of closely packed PS microspheres with an oxide precursor solution, followed by removal of the PS
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beads by sintering the film [44,45]. An ordered macroporous perovskite film-based semitransparent solar cell was also investigated by Chen et al., fabricated by removing the PS monolayer after filling perovskite into the pores, showing a promising efficiency of 11.7% with an active layer AVT of 36.5% [46]. Another approach is the fabrication of mesh-
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structured perovskite, providing transparency through the open regions of the mesh. Aharon et al. and Rahmany et al. fabricated mesh-patterned perovskite layers using the direct meshassisted assembly deposition method, exhibiting PCE of 5% and AVT of 20% [47,48]. Nanostructured absorber-based semitransparent perovskite solar cells
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To increase the performance of semitransparent solar cell devices, strategies for maximizing the PCE at a certain whole-device transmittance are required. One of the methods for achieving this concept is to structure the semitransparent perovskite absorber at the nanometer scale for better charge collection efficiency by increasing the charge
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transport/extraction rate through 1-D structure or by blending the perovskite absorber and the
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charge transport material (Figure 2c). A perovskite-phenyl-C61-butyric acid methyl ester (PCBM) hybrid structure in which PCBM penetrated into the perovskite grain boundaries
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was reported for better charge extraction through the increased PCBM/perovskite interfaces
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[49]. Xiao et al. also incorporated mesoporous TiO2 in the perovskite-PCBM hybrid structure, showing a PCE of 8.21% and AVT of 23% [50]. A blended structure with an oxide material
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based on a perovskite-NiO composite structure to enhance the hole extraction rate was also investigated, revealing a high PCE of 10.06% and AVT of 27% [51]. A well-ordered perovskite nanostructure for efficient semitransparent solar cell was
also suggested. Vertically aligned nanopillar-type perovskite was fabricated by employing an anodized aluminium oxide (AAO) template as an insulating scaffold layer [52,53]. This concept was based on the combined advantages of the enhanced charge transport/extraction
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properties of 1-D structures and increased transmittance due to vertically arrayed nanopillar absorber structures, allowing for facile charge transport and reduced reflectance. This structure exhibited exceptional performance with PCEs of 9.6% and a whole-device AVT of 33.4%, with significantly reduced haziness. Also, the nanopillar-based solar cell showed less
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J-V hysteresis than that of the planar structure, induced by ion diffusion inhibition due to the decreased defect density. Conclusions and outlook
Significant progress in semitransparent perovskite solar cells has been achieved. Various
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strategies using conventional methods or unique technologies for providing transparency to light absorber have been demonstrated, revealing high efficiencies of 10% as well as average visible light transparencies of 30%. An overview of semitransparent perovskite solar cells
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developed for the structuring of light absorbers is summarized in Figure 3 and Table 1. This summary clearly indicates that the performance of semitransparent perovskite solar cell
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technology has reached a mature stage. However, to open the markets of solar windows based on these perovskite absorbers, other issues, such as degradation of perovskite due to moisture
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or constant illumination, high production costs by use of vacuum deposited top/bottom
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transparent electrodes, and deteriorated performance when scaling up into large area devices, should be also well addressed prior to their full exploitation.
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Firstly, since long-term stability of solar cells is a prerequisite for commercialization,
the various efforts to achieve better stability have been pursued. In the case of moisture stability, encapsulating the device using an atomic layer deposition technique or forming a superhydrophobic coating on the upper layer of the perovskite could be candidates for preventing moisture penetration. Perovskite absorber degradation induced by halide ion migration is another issue to be resolved, and this could be improved by fabricating high-
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quality perovskite crystal grains or mixing a cation or halide of perovskite, interrupting the halide ion diffusion, all of which have been successfully investigated for opaque perovskite solar cells. In addition, efficiently functioning transparent electrodes with low-cost materials and
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an inexpensive fabrication process should be developed for reducing manufacturing costs while maintaining high performance of semitransparent solar cells. Although low cost transparent electrodes, such as metal nanowires or carbon-based electrodes, for semitransparent solar cells have been reported, whole devices based on inexpensive
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electrodes for both the top and bottom sides have been rarely reported. The main hurdle for their realization is that the perovskite phase easily dissolves in various polar solvents and decomposes when annealed over 100 ℃, impeding post-annealing. Therefore, research
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focused on adopting or finding low-cost transparent electrodes for both sides without damaging the perovskite absorber is in high demand.
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Finally, the primary issue for solution-processable perovskite scale-up production is
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the control of the uniform absorber film formation over large areas, overcoming the complex growth behavior of perovskite films. Moreover, a semitransparent absorber should be ultra-
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thin (below 100 nm) or even involve micro/nanoscale structuring. These requirements pose a great hurdle in large area absorber fabrication compared to conventional opaque solar cell
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fabrication. Scale-up technology including roll-to-roll fabrication for opaque perovskite solar cells and modules has been recently developed close to the commercialization level. Similar approaches should be carried out for exploiting the potential promising applications based on semitransparent perovskite solar cells. Conflict of interest
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None exists for this review. Acknowledgments This work was supported by a grant from the National Research Foundation of Korea funded by the Korean government (MISP) (No. 2012R1A3A2026417). This research was also
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partially supported by the Graduate School of YONSEI University Research Scholarship Grants in 2018. References and recommended reading
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Papers of particular interest, published within the period of review, have been highlighted as: •Paper of special interest. ••Paper of outstanding interest.
1. Kojima A, Teshima K, Shirai Y, Miyasaka T: Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J Am Chem Soc 2009, 131:6050-6051.
M
•• First report of using organometal halide perovskite as a solar cell.
2. Im JH, Lee CR, Lee JW, Park SW, Park NG: 6.5% efficient perovskite quantum-dot-
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sensitized solar cell. Nanoscale 2011, 3:4088-4093. 3. Edri E, Kirmayer S, Henning A, Mukhopadhyay S, Gartsman K, Rosenwaks Y, Hodes G, Cahen D: Why Lead Methylammonium Tri-Iodide Perovskite-Based Solar Cells
PT
Require a Mesoporous Electron Transporting Scaffold (but Not Necessarily a Hole Conductor). Nano Lett 2014, 14:1000-1004.
CE
4. Stranks SD, Eperon GE, Grancini G, Menelaou C, Alcocer MJP, Leijtens T, Herz LM, Petrozza A, Snaith HJ: Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in
AC
an Organometal Trihalide Perovskite Absorber. Science 2013, 342:341-344.
5. Kim HS, Lee CR, Im JH, Lee KB, Moehl T, Marchioro A, Moon SJ, Humphry-Baker R, Yum JH, Moser JE, et al.: Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%. Sci Rep 2012, 2:591. •• First demonstration of a solid hole transport layer, showing higher efficiency and stability of the perovskite solar cell. 6. Xing GC, Mathews N, Sun SY, Lim SS, Lam YM, Gratzel M, Mhaisalkar S, Sum TC:
9
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Long-Range Balanced Electron- and Hole-Transport Lengths in Organic-Inorganic CH3NH3PbI3. Science 2013, 342:344-347. •• First demonstration of a solid hole transport layer, showing higher efficiency and stability of the perovskite solar cell. 7. Lee MM, Teuscher J, Miyasaka T, Murakami TN, Snaith HJ: Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science 2012,
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338:643-647.
8. Norton B, Eames PC, Mallick TK, Huang MJ, McCormack SJ, Mondol JD, Yohanis YG: Enhancing the performance of building integrated photovoltaics. Sol Energy 2011, 85:1629-1664.
9. Vats K, Tiwari GN: Energy and exergy analysis of a building integrated
AN US
semitransparent photovoltaic thermal (BISPVT) system. Appl Energy 2012, 96:409416.
10. Xue QF, Xia RX, Brabec CJ, Yip HL: Recent advances in semi-transparent polymer and perovskite solar cells for power generating window applications. Energy Environ Sci 2018, 11:1688-1709.
Adv Mater 2017, 29:1700192.
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11. Tai QD, Yan F: Emerging Semitransparent Solar Cells: Materials and Device Design.
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12. Beiley ZM, McGehee MD: Modeling low cost hybrid tandem photovoltaics with the potential for efficiencies exceeding 20%. Energy Environ Sci 2012, 5:9173-9179.
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13. Chen CC, Dou LT, Gao J, Chang WH, Li G, Yang Y: High-performance semitransparent polymer solar cells possessing tandem structures. Energy Environ Sci
CE
2013, 6:2714-2720.
14. Chen B, Zheng XP, Bai Y, Padture NP, Huang JS: Progress in Tandem Solar Cells
AC
Based on Hybrid Organic-Inorganic Perovskites. Adv Energy Mater 2017, 7:1602400. 15. Quiroz COR, Bronnbauer C, Levchuk I, Hou Y, Brabec CJ, Forberich K: Coloring Semitransparent Perovskite Solar Cells via Dielectric Mirrors. ACS Nano 2016, 10:5104-5112.
16. You P, Liu ZK, Tai QD, Liu SH, Yan F: Efficient Semitransparent Perovskite Solar Cells with Graphene Electrodes. Adv Mater 2015, 27:3632-3638. 17. Guo F, Azimi H, Hou Y, Przybilla T, Hu MY, Bronnbauer C, Langner S, Spiecker E, Forberich K, Brabec CJ: High-performance semitransparent perovskite solar cells with solution-processed silver nanowires as top electrodes. Nanoscale 2015, 7:1642-
10
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1649. 18. Zhao J, Brinkmann KO, Hu T, Pourdavoud N, Becker T, Gahlmann T, Heiderhoff R, Polywka A, Gorrn P, Chen Y, et al.: Self-Encapsulating Thermostable and AirResilient Semitransparent Perovskite Solar Cells. Adv Energy Mater 2017, 7:1602599. 19. Li FR, Xu Y, Chen W, Xie SH, Li JY: Nanotube enhanced carbon grids as top electrodes for fully printable mesoscopic semitransparent perovskite solar cells. J
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Mater Chem A 2017, 5:10374-10379.
20. Fang YS, Wu ZC, Li J, Jiang FY, Zhang K, Zhang YL, Zhou YH, Zhou J, Hu B: HighPerformance Hazy Silver Nanowire Transparent Electrodes through Diameter Tailoring for Semitransparent Photovoltaics. Adv Func Mater 2018, 28:1705409.
21. Jung JW, Chueh CC, Jen AKY: High-Performance Semitransparent Perovskite Solar
AN US
Cells with 10% Power Conversion Efficiency and 25% Average Visible Transmittance Based on Transparent CuSCN as the Hole-Transporting Material. Adv Energy Mater 2015, 5:1500486.
22. Fu F, Feurer T, Weiss TP, Pisoni S, Avancini E, Andres C, Buecheler S, Tiwari AN: Higheffciency inverted semi-transparent planar perovskite solar cells in substrate
M
configuration. Nat Energy 2017, 2:16190.
23. Chang CY, Lee KT, Huang WK, Siao HY, Chang YC: High-Performance, Air-Stable,
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Low-Temperature Processed Semitransparent Perovskite Solar Cells Enabled by Atomic Layer Deposition. Chem Mater 2015, 27:5122-5130.
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24. Chang CY, Chang YC, Huang WK, Lee KT, Cho AC, Hsu CC: Enhanced Performance and Stability of Semitransparent Perovskite Solar Cells Using Solution-Processed
CE
Thiol-Functionalized Cationic Surfactant as Cathode Buffer Layer. Chem Mater 2015, 27:7119-7127.
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25. Xue QF, Bai Y, Liu MY, Xia RX, Hu ZC, Chen ZM, Jiang XF, Huang F, Yang SH, Matsuo Y, et al.: Dual Interfacial Modifications Enable High Performance Semitransparent Perovskite Solar Cells with Large Open Circuit Voltage and Fill Factor. Adv Energy Mater 2017, 7:1770047.
26. Traverse CJ, Pandey R, Barr MC, Lunt RR: Emergence of highly transparent photovoltaics for distributed applications. Nat Energy 2017, 2:849-860. •• Comprehensive review on transparent or semitransparent photovoltaics for real application. 27. Lee K-T, Guo L, Park H: Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells. Molecules 2016, 21:475.
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28. Shin DH, Jang CW, Lee HS, Seo SW, Choi SH: Semitransparent Flexible Organic Solar Cells Employing Doped-Graphene Layers as Anode and Cathode Electrodes. ACS Appl Mater Interfaces 2018, 10:3596-3601. 29. Sun J, Jasieniak JJ: Semi-transparent solar cells. J Phys D: Appl Phys 2017, 50:093001. 30. Quiroz COR, Levchuk L, Bronnbauer C, Salvador M, Forberich K, Heumuller T, Hou Y, Schweizer P, Spiecker E, Brabec CJ: Pushing efficiency limits for semitransparent
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perovskite solar cells. J Mater Chem A 2015, 3:24071-24081.
31. Della Gaspera E, Peng Y, Hou QC, Spiccia L, Bach U, Jasieniak JJ, Cheng YB: Ultrathin high efficiency semitransparent perovskite solar cells. Nano Energy 2015, 13:249-257.
32. Bag S, Durstock MF: Efficient semi-transparent planar perovskite solar cells using a
AN US
'molecular glue'. Nano Energy 2016, 30:542-548.
33. Ono LK, Leyden MR, Wang SH, Qi YB: Organometal halide perovskite thin films and solar cells by vapor deposition. J Mater Chem A 2016, 4:6693-6713. 34. Roldan-Carmona C, Malinkiewicz O, Betancur R, Longo G, Momblona C, Jaramillo F, Camacho L, Bolink HJ: High efficiency single-junction semitransparent perovskite
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solar cells. Energy Environ Sci 2014, 7:2968-2973.
35. Ono LK, Wang SH, Kato Y, Raga SR, Qi YB: Fabrication of semi-transparent
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perovskite films with centimeter-scale superior uniformity by the hybrid deposition method. Energy Environ Sci 2014, 7:3989-3993.
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• First report of semitransparent perovskite solar cell using the evaporation method. 36. Kim GM, Tatsuma T: Semitransparent Solar Cells with Ultrasmooth and Low-
CE
Scattering Perovskite Thin Films. J Phys Chem C 2016, 120:28933-28938. 37. Heo JH, Han HJ, Lee M, Song M, Kim DH, Im SH: Stable semi-transparent
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CH3NH3PbI3 planar sandwich solar cells. Energy Environ Sci 2015, 8:2922-2927. 38. Guo YL, Shoyama K, Sato W, Nakamura E: Polymer Stabilization of Lead(II) Perovskite Cubic Nanocrystals for Semitransparent Solar Cells. Adv Energy Mater 2016, 6:1502317.
39. Zhang S, Lu YT, Lin BC, Zhu YY, Zhang KZ, Yuan NY, Ding JN, Fang BJ: PVDF-HFP additive for visible-light-semitransparent perovskite films yielding enhanced photovoltaic performance. Sol Energy Mater Sol Cells 2017, 170:178-186. 40. Eperon GE, Burlakov VM, Goriely A, Snaith HJ: Neutral Color Semitransparent Microstructured Perovskite Solar Cells. ACS Nano 2014, 8:591-598.
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•• This work shows the island structured perovskite based neutral color semitransparent solar cell fot the first time. 41. Eperon GE, Bryant D, Troughton J, Stranks SD, Johnston MB, Watson T, Worsley DA, Snaith HJ: Efficient, Semitransparent Neutral-Colored Solar Cells Based on Microstructured Formamidinium Lead Trihalide Perovskite. J Phys Chem Lett 2015, 6:129-138.
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42. Horantner MT, Nayak PK, Mukhopadhyay S, Wojciechowski K, Beck C, McMeekin D, Kamino B, Eperon GE, Snaith HJ: Shunt-Blocking Layers for Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2016, 3:1500837.
43. Heo JH, Jang MH, Lee MH, Han HJ, Kang MG, Lee ML, Im SH: Efficiency enhancement of semi-transparent sandwich type CH3NH3PbI3 perovskite solar cells
AN US
with island morphology perovskite film by introduction of polystyrene passivation layer. J Mater Chem A 2016, 4:16324-16329.
44. Horantner MT, Zhang W, Saliba M, Wojciechowski K, Snaith HJ: Templated microstructural growth of perovskite thin films via colloidal monolayer lithography. Energy Environ Sci 2015, 8:2041-2047.
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45. Zhang LJ, Horantner MT, Zhang W, Yan QF, Snaith HJ: Near-neutral-colored semitransparent perovskite films using a combination of colloidal self-assembly and
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plasma etching. Sol Energy Mater Sol Cells 2017, 160:193-202. 46. Chen BX, Rao HS, Chen HY, Li WG, Kuang DB, Su CY: Ordered macroporous
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CH3NH3PbI3 perovskite semitransparent film for high-performance solar cells. J Mater Chem A 2016, 4:15662-15669.
CE
47. Aharon S, Layani M, Cohen BE, Shukrun E, Magdassi S, Etgar L: Self-Assembly of Perovskite for Fabrication of Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2015, 2:1500118.
AC
• A unique structure of perovskite mesh is investigated for semitransparent solar cell. 48. Rahmany S, Layani M, Magdassi S, Etgar L: Fully functional semi-transparent perovskite solar cell fabricated in ambient air. Sustain Energy Fuels 2017, 1:21202127. 49. Li C, Sleppy J, Dhasmana N, Soliman M, Tetard L, Thomas J: A PCBM-assisted perovskite growth process to fabricate high efficiency semitransparent solar cells. J Mater Chem A 2016, 4:11648-11655. 50. Xiao S, Chen HN, Jiang FY, Bai Y, Zhu ZL, Zhang T, Zheng XL, Qian GY, Hu C, Zhou
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YH, et al.: Hierarchical Dual-Scaffolds Enhance Charge Separation and Collection for High Efficiency Semitransparent Perovskite Solar Cells. Adv Mater Interfaces 2016, 3:1600484. 51. Wang YS, Mahmoudi T, Yang HY, Bhat KS, Yoo JY, Hahn YB: Fully-ambient-processed mesoscopic semitransparent perovskite solar cells by islands-structure-MAPbI(3x)Cl(x)-NiO
composite and Al2O3/NiO interface engineering. Nano Energy 2018, 49:59-
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66.
52. Kwon HC, Kim A, Lee H, Lee D, Jeong S, Moon J: Parallelized Nanopillar Perovskites for Semitransparent Solar Cells Using an Anodized Aluminum Oxide Scaffold. Adv Energy Mater 2016, 6:1601055.
•• Vertically aligned 1-D perovskite based semitransparent solar cell was demonstrated for
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the first time.
53. Kwon HC, Yang W, Lee D, Ahn J, Lee E, Ma S, Kim K, Yun SC, Moon J: Investigating Recombination and Charge Carrier Dynamics in a One-Dimensional Nanopillared
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CE
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Perovskite Absorber. ACS Nano 2018, 12:4233-4245.
Figure 1. Device structure and a photography of semitransparent perovskite solar cell, and
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various research strategies for enhancing performance.
Figure 2. Fabrication strategies and optical/electrical effects for three different semitransparent perovskite absorber structures: (a) ultra-thin absorber, (b) microstructured
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absorber, and (c) nanostructured absorber.
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Figure 3. Whole-device AVT versus PCE plot of semitransparent perovskite solar cells whose themes are focused on the structuring of the light absorber.
Table 1. Summary of semitransparent perovskite solar cells with various light absorber
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structures.
Fabrication method
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Perovskite absorber type
Anti-solvent dipping Gas-assisted spincoating
Two-step spin-coating Evaporation
Thin film Evaporation Vacuum assisted drying HI additive PVP additive
Device structure Ag nanowire/ZnO/PCBM/ CH3NH3PbI3-XClX/PEDOT:PSS/ITO MoO3/Au/MoO3/spiro-OMeTAD/ CH3NH3PbI3/c-TiO2/FTO Ag/AUHa/C60/PCBM/CH3NH3PbI3/ PEDOT:PSS/ITO LiF/Au/PCBM60/CH3NH3PbI3/ polyTPDb/PEDOT:PSS/ITO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ c-TiO2/FTO MoO3/Ag/BCP/PCBM/CH3NH3PbI3/ PEDOT:PSS/ITO ITO/PEDOT:PSS/PTAAc/ CH3NH3PbI3/c-TiO2/FTO Au/polyethylenimine/PCBM/CYTOPd/ CH3NH3PbI3-XClX/PEDOT:PSS/ITO
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Average visible light transmittance
Power conversion Reference efficiency
28-46%
3.55-8.12%
30
7-31%
5.3-13.6%
31
12-47%
4.5-13.3%
32
10-35.4%
3.39-7.73%
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-
6.3-9.9%
35
-
6.87-10.66%
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12.6-15.9%
6.3-17.3%
37
34%
5.36%
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Dewetting (Island) Dewetting (Island) Dewetting (Island) Dewetting (Island)
Nanostructure
Micro-pore oxide template Micro-pore oxide template Macroporous perovskite Mesh-assisted assembly (grid) Mesh-assisted assembly (grid) PCBM-assisted perovskite growth (hybrid) PCBM-assisted perovskite growth (hybrid)
Au/spiro-OMeTAD/CH3NH3PbI3 grid/ meso-TiO2/c-TiO2/FTO
Mesoporous scaffold Anodized aluminum oxide scaffold (nanopillar)
MoO3/Au/MoO3/spiro-OMeTAD/ CH3NH3PbI3 grid/meso-Al2O3/ meso-TiO2/c-TiO2/FTO Au/PCBM/CH3NH3PbI3-PEDOT:PSS hybrid/ PEDOT:PSS/ITO PEDOT:PSS/spiro-OMeTAD/ CH3NH3PbI3-PEDOT:PSS hybrid/ meso-TiO2/c-TiO2/FTO Au/spiro-OMeTAD/ CH3NH3PbI3-XClX-NiO composite/ meso-Al2O3/meso-TiO2/c-TiO2/FTO
32.40%
8.80%
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7-30%
3.5-8%
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28%
5.20%
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38%
6.10%
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20.90%
10.60%
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9.5%, 4.5%
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10.30%
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28%, 37% (without top electrode) 38% (only light absorb layer) 36.5% (only light absorb layer) 19-64% (without top electrode and spiro-OMeTAD)
11.70%
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0.83-4.98%
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26%
5.50%
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3%, 18%
9.1%, 12.2%
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23%
8%
50
27%
10.06%
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33.4-46.0%
5.7-9.6%
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Microstructure
Au/spiro-OMeTAD/CH3NH3PbI3/ c-TiO2/FTO Au/spiro-OMeTAD/CH3NH3PbI3-XClX/ c-TiO2/FTO Au/spiro-OMeTAD/HC(NH2)2PbI3/ c-TiO2/FTO Ni grid/spiro-OMeTAD/CH3NH3PbI3/ octadecyl-siloxane/c-TiO2/FTO ITO/PEDOT:PSS/PTAA/CH3NH3PbI3/ PS/c-TiO2/FTO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ SiO2 honeycomb scaffold/c-TiO2/FTO Ag/spiro-OMeTAD/CH3NH3PbI3-XClX/ SiO2 honeycomb scaffold/c-TiO2/FTO Au/spiro-OMeTAD/CH3NH3PbI3/ c-TiO2/FTO
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PVDF-HFPe additive
ITO/MoOX/spiro-OMeTAD/ CH3NH3PbI3-XClX+AAO/c-TiO2/FTO
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a: 11-amino-1-undecanethiol hydrochloride, b: poly[N,N0-bis(4-butylphenyl)-N,N0-bis(phenyl)benzidine], c: Poly[bis(4phenyl)(2,4,6-trimethylphenyl)amine], d: commercial fluorous polymer, e: poly(vinylidenefluoride-co-hexafluoropropylene)
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