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Two-step method for preparing all-inorganic CsPbBr3 perovskite film and its photoelectric detection application
Materials Letters 186 (2017) 243–246
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
crossmark
Two-step method for preparing all-inorganic CsPbBr3 perovskite film and its photoelectric detection application Dongjue Liua, Zhiping Hua, Wei Hua, Peihua Wangyangb, Kuai Yuc, Mengqing Wena, ⁎ Zhiqiang Zua, Juan Liua, Ming Wanga, Weiwei Chena, Miao Zhoua, Xiaosheng Tanga, , a Zhigang Zang a Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China b Sichuan Province Key Laboratory of Information Materials and Devices Application, College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, China c College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060, China
A R T I C L E I N F O
A BS T RAC T
Keywords: CsPbBr3 perovskite film Photoelectric detection Semiconductor
All-inorganic perovskite CsPbBr3 films composed of uniform nanocubes were prepared by two-step method and the corresponding photoelectric detection devices were further designed for studying the photoresponse property. The SEM, XRD, PL and Abs results showed the pure CsPbBr3 films could keep high stability under ambient environment. Furthermore, the excellent photoresponse of CsPbBr3 film based devices showed relatively strong photoresponse, comparable short rise-time (0.60 s) and decay-time (0.64 s), which is attributed to the effective electron-hole separation and fast electrical transportation. Moreover, the stable multiple-cycles ON-OFF switching behavior implies its excellent reproducibility.
1. Introduction It is well known that perovskites materials were widely used in solar cell [1,2], light-emitting diode [3], laser [4] and photodetector [5] because of their favorable properties, such as tunable band gap, strong optical absorption, ambipolar charge transport, and long electron-hole diffusion length [6–8]. However, the intrinsic thermal instability of methylammonium (MA) and formamidinium (FA) based perovskite materials limit the further development of hybrid perovskites based optoelectronic devices [9]. Compared with the thermally degradation of hybrid perovskite, the all-inorganic perovskite has recently been proposed as an alternative candidate for optoelectronics because of their higher chemical stability and interesting electronic properties. One model system is cesium lead halide (CsPbX3, X=Cl, Br, and I), which has triggered a surge of investigations [1,2,10]. In previous works, most of the perovskites materials based optoelectronic devices were prepared by solution process approach, which would refer to the long-chain organic ligands and spin coating method [4,11]. Moreover, the inorganic perovskite nanocrystal (NCs) photodetector showed relatively low photoresponse properties such as the slow rise-decay time (few seconds) with much clutter, which could be ascribed to the long-chain organic ligands on the surface of perovskite NCs [11].
⁎
In this work, we reported a facile and low-cost method to fabricate high-performance CsPbBr3 film with high quality based photodetector devices, which was prepared by a substrate growth method free from redundant ligands. And the as-prepared CsPbBr3 perovskite film showed high stability under ambient environment. As for performance, the CsPbBr3 film based devices showed relatively good photoresponse properties, which probably can be attributed to the direct contact between ITO substrate and CsPbBr3 film and lead effective electronhole separation and fast electrical transportation. Moreover, the stable multiple-cycles ON-OFF switching behavior implies its excellent reproducibility. These results offer a new playground to understand and design perovskite materials for future optoelectronic devices. 2. Preparation of CsPbBr3 film ITO (or Si) transparent conducting substrates were cleaned by sequential 20 min sonication in warm deionized water, acetone, and isopropanol. After drying under a nitrogen flow at atmosphere, substrates were treated with UV-ozone for 15 min. Then annealed at 75 °C before using. The CsPbBr3 films were prepared by a 2-step sequential deposition technique. Firstly, 30 mg CsBr was dissolved in 2 mL methanol and
Corresponding author. E-mail address: [email protected] (X. Tang).
http://dx.doi.org/10.1016/j.matlet.2016.10.015 Received 9 September 2016; Received in revised form 3 October 2016; Accepted 4 October 2016 Available online 05 October 2016 0167-577X/ © 2016 Elsevier B.V. All rights reserved.
Materials Letters 186 (2017) 243–246
D. Liu et al.
top of the films after recrystallization and there are nearly no any cracks could be found when reaction for 15 min, which demonstrated dense film were successfully prepared. The XRD measurements were conducted to investigate the crystal structure of these samples. As shown in Fig. 2(a), the obvious peak located at 29.42° which could be assigned to the orthorhombic CsPbBr3 structure. Accordingly, the intensity of this peak became sharper, which implied the ratio of orthorhombic perovskite CsPbBr3 structure crystals were increased as prolonged reaction time. Meanwhile, the gradually decreasing peak of 11.67°, which can be assigned to the tetragonal CsPb2Br5 was observed. Based on the two corresponding change, it could be concluded that the transformation from CsPb2Br5 to CsPbBr3 happened when the reaction continued. And this similar process could be explained as that the inherent 3D perovskite structural of CsPbBr3 has hardly any van der Waals gaps comparing to CsPb2Br5 with the structure similar to layered double hydroxides
heated for 10 min in sealed container. Subsequently, 367 mg PbBr2 in 1 mL DMF was stirred on a hot plate at 75 °C for 5 h, and then was filtered by using a 0.22 µm pore size PTFE filter and immediately for using. The PbBr2 layer was spin-coated at 4000 rpm for 40 s on this well-cleaned preheated (75 °C) ITO (or Si) and dried at 75 °C for 30 min. After drying, the substrates were dipped for 5–15 min in a heated (50 °C) solution of 15 mg/mL CsBr and then annealing at 180 °C on the hot plate immediately. 3. Result and discussion In this study, the CsPbBr3 crystal films with uniform and highcrystallized quality were successfully fabricated. From the top-view SEM images [Fig. 1(a–f)] for perovskite micro-nano crystal films reaction for 5, 10 and 15 min respectively, it could be observed the CsPbBr3 films were composed of unique cube shape with different size. And the low magnified SEM results display the comparable smooth surface of the as-prepared CsPbBr3 film [Fig. 1(a–c)]. It is observed that the nanocrystals with cube shape appeared within the first 5 min, and the size of perovskite nanocrystals were distributed in the range of 100–600 nm. The nanocrystals grew bigger and the surface gradually became smooth when reaction for 10 min. The intermitting at the surface is smaller further indicated the film is denser and thicker, which probably could be ascribed to the increased crystallinity of the perovskite film. Moreover, lots of huge single crystals formed on the
Table 1 The decay times of a single photocurrent response with and without the irradiation of CsPbBr3 crystal films under different growth times. Growth time (min)
5 min
10 min
15 min
Decay timeτ1 (s) Decay timeτ2 (s)
0.52 0.52
0.47 0.42
0.42 0.38
Fig. 1. Top-view low resolution and magnified SEM images for perovskite films covering on the ITO substrate with growth time of (a, d) 5 min, (b, e) 10 min and (c, f) 15 min.
Fig. 2. Properties of CsPbBr3 films under different growth times, (a) typical XRD patterns, (b) absorbance spectra, (c) photoresponses.
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D. Liu et al.
Fig. 3. The photoluminescence (a) and absorbance (b) spectra from 1 month to 6 months of the obtained perovskite film samples, (c) the photoelectric response with and without the irradiation and (d) schematic profiles of a single photocurrent response with and without the irradiation of the obtained samples with 15 min growth time.
[1,12]. Therefore, the pure CsPbBr3 films with high crystalline could be obtained under reaction for 15 min at 180 °C annealing temperature. And, such kind of crystalline materials principal role play p halogen states coordinated by heavy cations and principal role is p played by intrinsic cationic defects [13]. Fig. 2(b) showed the distinct enhancing absorbance, which testified the high crystalline semiconductor materials could achieve comparable wide absorbance compared to polycrystalline or amorphous thin films, and this phenomenon was consistent with previously studies [14]. Fig. 2(c) and [Table 1] is the photocurrents results of various all-inorganic films prepared at different reaction time under continuous wave laser (excitation at 532 nm with an optical power of 20 mW) by applying an anodic bias potential of +8 V. The results showed that the perovskite films was sensitive to the laser irradiation, and relatively higher transient photocurrent of the sample (15 min) indicated the charge density from the separation electron-hole pairs were high and which could ascribed to the high absorbance intensity [Fig. 2(b)]. As we can see, PL and Abs spectra for the as-prepared CsPbBr3 films have little change (nearly no shift), indicating that the CsPbBr3 films have nice photo-stability with several months under ambient environment. It indicated its potential application in the stable optoelectronic devices. Fig. 3(c) and (d) were the photoelectric response property with and without the irradiation of the CsPbBr3 films at growth time of 15 min. The multiple-cycles ON-OFF switching behavior demonstrated these prepared photodetectors are robust and reproducible. While in Fig. 3(d), the relatively large photocurrent density tip (Jin) due to the sudden photogenerated separation of electron–hole pairs when the light was turn on, whereafter, the photocurrent decreased to initial state when the light turn off. A steady state photocurrent density (Jst) is subsequently achieved since the equilibrium between the electron diffusion rate and its generation rate.
The photocurrent density tip state and steady state photocurrent density are 2.90 and 2.09 times larger than that of the light off state and the results show that rise and decay times are τ1=0.60 s τ2=0.64 s. 4. Conclusions In this study, dense and smooth all-inorganic perovskite CsPbBr3 films with high stability under atmosphere have been successfully prepared by two-step sequential deposition technique. The composition and crystal orientation transformation observed in this study explained the different photoresponse properties for these samples. Moreover, the distinct recrystallization phenomenon observed at reaction of 15 min is making for optimizing the composition and structure of CsPbBr3 films. As for performance, the excellent photoresponse of CsPbBr3 film based devices showed relatively strong photoresponse, comparable short rise-time (0.60 s) and decay-time (0.64 s). Acknowledgment This work is supported by National Natural Science Foundation of China (Grant No. 61475169, 61520106012, 61574024), 100 Talents Program of CAS, the Fundamental Research Funds for the Central Universities, initial funding of Hundred Young Talents Plan at Chongqing University (0210001104430), the Project-sponsored by SRF for ROCS, SEM (0210002409003). References [1] R.J. Sutton, G.E. Eperon, L. Miranda, E.S. Parrott, B.A. Kamino, J.B. Patel, Bandgap-tunable cesium lead halide perovskites with high thermal stability for efficient solar cells, Adv. Energy Mater. 6 (2016).
245
Materials Letters 186 (2017) 243–246
D. Liu et al.
emitting field-effect transistor, Nat. Commun. 6 (2015). [9] B. Conings, J. Drijkoningen, N. Gauquelin, A. Babayigit, J. D’Haen, L. D’Olieslaeger, Intrinsic thermal instability of methylammonium lead trihalide perovskite, Adv. Energy Mater. 5 (15) (2015). [10] L. Protesescu, S. Yakunin, M.I. Bodnarchuk, F. Krieg, R. Caputo, C.H. Hendon, M.V. Kovalenko, Nanocrystals of cesium lead halide perovskites (CsPbX3, X=Cl, Br, and I): novel optoelectronic materials showing bright emission with wide color gamut, Nano Lett. 15 (2015) 3692–3696. [11] D.H. Kwak, D.H. Lim, H.S. Ra, P. Ramasamy, J.S. Lee, High performance hybrid graphene–CsPbBr3−xIx perovskite nanocrystal photodetector, RSC Adv. 6 (2016). [12] K. Wang, L. Wu, L. Li, H. Yao, H. Qian, S. Yu, Large-scale synthesis of highly luminescent perovskite-related CsPb2Br5 nanoplatelets and their fast anion exchange, Angew. Chem. Int. Ed. 55 (29) (2016) 8328–8332. [13] I.V. Kityk, O. Khyszun, M. Piasecki, O. Parasyuk, Single crystal growth and electronic structure of TlPbI3, Mater. Chem. Phys. 172 (2016) 165–172. [14] A. Luque, S. Hegedus, Handbook of Photovoltaic Science and Engineering, Wiley John+Sons, New York, 2011.
[2] M. Saliba, T. Matsui, J.Y. Seo, K. Domanski, J.P. Correabaena, M.K. Nazeeruddin, Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency, Energ. Environ. Sci. 9 (6) (2016) 1989–1997. [3] Y.C. Xin, D. Cortecchia, J. Yin, A. Bruno, C. Soci, Lead iodide perovskite lightemitting field-effect transistor, Nat. Commun. 6 (2015). [4] G. Xing, N. Mathews, S.S. Lim, N. Yantara, X. Liu, D. Sabba, Low-temperature solution-processed wavelength-tunable perovskites for lasing, Nat. Mater. 13 (5) (2014) 476–480. [5] Y. Lee, J. Kwon, E. Hwang, C.H. Ra, W.J. Yoo, J.H. Ahn, J.H. Cho, Highperformance perovskite-graphene hybrid photodetector, Adv. Mater. 27 (2015) 41–46. [6] T. Leijtens, G.E. Eperon, N.K. Noel, S.N. Habisreutinger, A. Petrozza, H.J. Snaith, Stability of metal halide perovskite solar cells, Adv. Energy Mater. 5 (2015). [7] J. Burschka, N. Pellet, S.J. Moon, R. Humphry-Baker, P. Gao, M.K. Nazeeruddin, M. Grätzel, Sequential deposition as a route to high-performance perovskitesensitized solar cells, Nature 499 (2013) 316–319. [8] X.Y. Chin, D. Cortecchia, J. Yin, A. Bruno, C. Soci, Lead iodide perovskite light-
246
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
crossmark
Two-step method for preparing all-inorganic CsPbBr3 perovskite film and its photoelectric detection application Dongjue Liua, Zhiping Hua, Wei Hua, Peihua Wangyangb, Kuai Yuc, Mengqing Wena, ⁎ Zhiqiang Zua, Juan Liua, Ming Wanga, Weiwei Chena, Miao Zhoua, Xiaosheng Tanga, , a Zhigang Zang a Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China b Sichuan Province Key Laboratory of Information Materials and Devices Application, College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, China c College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060, China
A R T I C L E I N F O
A BS T RAC T
Keywords: CsPbBr3 perovskite film Photoelectric detection Semiconductor
All-inorganic perovskite CsPbBr3 films composed of uniform nanocubes were prepared by two-step method and the corresponding photoelectric detection devices were further designed for studying the photoresponse property. The SEM, XRD, PL and Abs results showed the pure CsPbBr3 films could keep high stability under ambient environment. Furthermore, the excellent photoresponse of CsPbBr3 film based devices showed relatively strong photoresponse, comparable short rise-time (0.60 s) and decay-time (0.64 s), which is attributed to the effective electron-hole separation and fast electrical transportation. Moreover, the stable multiple-cycles ON-OFF switching behavior implies its excellent reproducibility.
1. Introduction It is well known that perovskites materials were widely used in solar cell [1,2], light-emitting diode [3], laser [4] and photodetector [5] because of their favorable properties, such as tunable band gap, strong optical absorption, ambipolar charge transport, and long electron-hole diffusion length [6–8]. However, the intrinsic thermal instability of methylammonium (MA) and formamidinium (FA) based perovskite materials limit the further development of hybrid perovskites based optoelectronic devices [9]. Compared with the thermally degradation of hybrid perovskite, the all-inorganic perovskite has recently been proposed as an alternative candidate for optoelectronics because of their higher chemical stability and interesting electronic properties. One model system is cesium lead halide (CsPbX3, X=Cl, Br, and I), which has triggered a surge of investigations [1,2,10]. In previous works, most of the perovskites materials based optoelectronic devices were prepared by solution process approach, which would refer to the long-chain organic ligands and spin coating method [4,11]. Moreover, the inorganic perovskite nanocrystal (NCs) photodetector showed relatively low photoresponse properties such as the slow rise-decay time (few seconds) with much clutter, which could be ascribed to the long-chain organic ligands on the surface of perovskite NCs [11].
⁎
In this work, we reported a facile and low-cost method to fabricate high-performance CsPbBr3 film with high quality based photodetector devices, which was prepared by a substrate growth method free from redundant ligands. And the as-prepared CsPbBr3 perovskite film showed high stability under ambient environment. As for performance, the CsPbBr3 film based devices showed relatively good photoresponse properties, which probably can be attributed to the direct contact between ITO substrate and CsPbBr3 film and lead effective electronhole separation and fast electrical transportation. Moreover, the stable multiple-cycles ON-OFF switching behavior implies its excellent reproducibility. These results offer a new playground to understand and design perovskite materials for future optoelectronic devices. 2. Preparation of CsPbBr3 film ITO (or Si) transparent conducting substrates were cleaned by sequential 20 min sonication in warm deionized water, acetone, and isopropanol. After drying under a nitrogen flow at atmosphere, substrates were treated with UV-ozone for 15 min. Then annealed at 75 °C before using. The CsPbBr3 films were prepared by a 2-step sequential deposition technique. Firstly, 30 mg CsBr was dissolved in 2 mL methanol and
Corresponding author. E-mail address: [email protected] (X. Tang).
http://dx.doi.org/10.1016/j.matlet.2016.10.015 Received 9 September 2016; Received in revised form 3 October 2016; Accepted 4 October 2016 Available online 05 October 2016 0167-577X/ © 2016 Elsevier B.V. All rights reserved.
Materials Letters 186 (2017) 243–246
D. Liu et al.
top of the films after recrystallization and there are nearly no any cracks could be found when reaction for 15 min, which demonstrated dense film were successfully prepared. The XRD measurements were conducted to investigate the crystal structure of these samples. As shown in Fig. 2(a), the obvious peak located at 29.42° which could be assigned to the orthorhombic CsPbBr3 structure. Accordingly, the intensity of this peak became sharper, which implied the ratio of orthorhombic perovskite CsPbBr3 structure crystals were increased as prolonged reaction time. Meanwhile, the gradually decreasing peak of 11.67°, which can be assigned to the tetragonal CsPb2Br5 was observed. Based on the two corresponding change, it could be concluded that the transformation from CsPb2Br5 to CsPbBr3 happened when the reaction continued. And this similar process could be explained as that the inherent 3D perovskite structural of CsPbBr3 has hardly any van der Waals gaps comparing to CsPb2Br5 with the structure similar to layered double hydroxides
heated for 10 min in sealed container. Subsequently, 367 mg PbBr2 in 1 mL DMF was stirred on a hot plate at 75 °C for 5 h, and then was filtered by using a 0.22 µm pore size PTFE filter and immediately for using. The PbBr2 layer was spin-coated at 4000 rpm for 40 s on this well-cleaned preheated (75 °C) ITO (or Si) and dried at 75 °C for 30 min. After drying, the substrates were dipped for 5–15 min in a heated (50 °C) solution of 15 mg/mL CsBr and then annealing at 180 °C on the hot plate immediately. 3. Result and discussion In this study, the CsPbBr3 crystal films with uniform and highcrystallized quality were successfully fabricated. From the top-view SEM images [Fig. 1(a–f)] for perovskite micro-nano crystal films reaction for 5, 10 and 15 min respectively, it could be observed the CsPbBr3 films were composed of unique cube shape with different size. And the low magnified SEM results display the comparable smooth surface of the as-prepared CsPbBr3 film [Fig. 1(a–c)]. It is observed that the nanocrystals with cube shape appeared within the first 5 min, and the size of perovskite nanocrystals were distributed in the range of 100–600 nm. The nanocrystals grew bigger and the surface gradually became smooth when reaction for 10 min. The intermitting at the surface is smaller further indicated the film is denser and thicker, which probably could be ascribed to the increased crystallinity of the perovskite film. Moreover, lots of huge single crystals formed on the
Table 1 The decay times of a single photocurrent response with and without the irradiation of CsPbBr3 crystal films under different growth times. Growth time (min)
5 min
10 min
15 min
Decay timeτ1 (s) Decay timeτ2 (s)
0.52 0.52
0.47 0.42
0.42 0.38
Fig. 1. Top-view low resolution and magnified SEM images for perovskite films covering on the ITO substrate with growth time of (a, d) 5 min, (b, e) 10 min and (c, f) 15 min.
Fig. 2. Properties of CsPbBr3 films under different growth times, (a) typical XRD patterns, (b) absorbance spectra, (c) photoresponses.
244
Materials Letters 186 (2017) 243–246
D. Liu et al.
Fig. 3. The photoluminescence (a) and absorbance (b) spectra from 1 month to 6 months of the obtained perovskite film samples, (c) the photoelectric response with and without the irradiation and (d) schematic profiles of a single photocurrent response with and without the irradiation of the obtained samples with 15 min growth time.
[1,12]. Therefore, the pure CsPbBr3 films with high crystalline could be obtained under reaction for 15 min at 180 °C annealing temperature. And, such kind of crystalline materials principal role play p halogen states coordinated by heavy cations and principal role is p played by intrinsic cationic defects [13]. Fig. 2(b) showed the distinct enhancing absorbance, which testified the high crystalline semiconductor materials could achieve comparable wide absorbance compared to polycrystalline or amorphous thin films, and this phenomenon was consistent with previously studies [14]. Fig. 2(c) and [Table 1] is the photocurrents results of various all-inorganic films prepared at different reaction time under continuous wave laser (excitation at 532 nm with an optical power of 20 mW) by applying an anodic bias potential of +8 V. The results showed that the perovskite films was sensitive to the laser irradiation, and relatively higher transient photocurrent of the sample (15 min) indicated the charge density from the separation electron-hole pairs were high and which could ascribed to the high absorbance intensity [Fig. 2(b)]. As we can see, PL and Abs spectra for the as-prepared CsPbBr3 films have little change (nearly no shift), indicating that the CsPbBr3 films have nice photo-stability with several months under ambient environment. It indicated its potential application in the stable optoelectronic devices. Fig. 3(c) and (d) were the photoelectric response property with and without the irradiation of the CsPbBr3 films at growth time of 15 min. The multiple-cycles ON-OFF switching behavior demonstrated these prepared photodetectors are robust and reproducible. While in Fig. 3(d), the relatively large photocurrent density tip (Jin) due to the sudden photogenerated separation of electron–hole pairs when the light was turn on, whereafter, the photocurrent decreased to initial state when the light turn off. A steady state photocurrent density (Jst) is subsequently achieved since the equilibrium between the electron diffusion rate and its generation rate.
The photocurrent density tip state and steady state photocurrent density are 2.90 and 2.09 times larger than that of the light off state and the results show that rise and decay times are τ1=0.60 s τ2=0.64 s. 4. Conclusions In this study, dense and smooth all-inorganic perovskite CsPbBr3 films with high stability under atmosphere have been successfully prepared by two-step sequential deposition technique. The composition and crystal orientation transformation observed in this study explained the different photoresponse properties for these samples. Moreover, the distinct recrystallization phenomenon observed at reaction of 15 min is making for optimizing the composition and structure of CsPbBr3 films. As for performance, the excellent photoresponse of CsPbBr3 film based devices showed relatively strong photoresponse, comparable short rise-time (0.60 s) and decay-time (0.64 s). Acknowledgment This work is supported by National Natural Science Foundation of China (Grant No. 61475169, 61520106012, 61574024), 100 Talents Program of CAS, the Fundamental Research Funds for the Central Universities, initial funding of Hundred Young Talents Plan at Chongqing University (0210001104430), the Project-sponsored by SRF for ROCS, SEM (0210002409003). References [1] R.J. Sutton, G.E. Eperon, L. Miranda, E.S. Parrott, B.A. Kamino, J.B. Patel, Bandgap-tunable cesium lead halide perovskites with high thermal stability for efficient solar cells, Adv. Energy Mater. 6 (2016).
245
Materials Letters 186 (2017) 243–246
D. Liu et al.
emitting field-effect transistor, Nat. Commun. 6 (2015). [9] B. Conings, J. Drijkoningen, N. Gauquelin, A. Babayigit, J. D’Haen, L. D’Olieslaeger, Intrinsic thermal instability of methylammonium lead trihalide perovskite, Adv. Energy Mater. 5 (15) (2015). [10] L. Protesescu, S. Yakunin, M.I. Bodnarchuk, F. Krieg, R. Caputo, C.H. Hendon, M.V. Kovalenko, Nanocrystals of cesium lead halide perovskites (CsPbX3, X=Cl, Br, and I): novel optoelectronic materials showing bright emission with wide color gamut, Nano Lett. 15 (2015) 3692–3696. [11] D.H. Kwak, D.H. Lim, H.S. Ra, P. Ramasamy, J.S. Lee, High performance hybrid graphene–CsPbBr3−xIx perovskite nanocrystal photodetector, RSC Adv. 6 (2016). [12] K. Wang, L. Wu, L. Li, H. Yao, H. Qian, S. Yu, Large-scale synthesis of highly luminescent perovskite-related CsPb2Br5 nanoplatelets and their fast anion exchange, Angew. Chem. Int. Ed. 55 (29) (2016) 8328–8332. [13] I.V. Kityk, O. Khyszun, M. Piasecki, O. Parasyuk, Single crystal growth and electronic structure of TlPbI3, Mater. Chem. Phys. 172 (2016) 165–172. [14] A. Luque, S. Hegedus, Handbook of Photovoltaic Science and Engineering, Wiley John+Sons, New York, 2011.
[2] M. Saliba, T. Matsui, J.Y. Seo, K. Domanski, J.P. Correabaena, M.K. Nazeeruddin, Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency, Energ. Environ. Sci. 9 (6) (2016) 1989–1997. [3] Y.C. Xin, D. Cortecchia, J. Yin, A. Bruno, C. Soci, Lead iodide perovskite lightemitting field-effect transistor, Nat. Commun. 6 (2015). [4] G. Xing, N. Mathews, S.S. Lim, N. Yantara, X. Liu, D. Sabba, Low-temperature solution-processed wavelength-tunable perovskites for lasing, Nat. Mater. 13 (5) (2014) 476–480. [5] Y. Lee, J. Kwon, E. Hwang, C.H. Ra, W.J. Yoo, J.H. Ahn, J.H. Cho, Highperformance perovskite-graphene hybrid photodetector, Adv. Mater. 27 (2015) 41–46. [6] T. Leijtens, G.E. Eperon, N.K. Noel, S.N. Habisreutinger, A. Petrozza, H.J. Snaith, Stability of metal halide perovskite solar cells, Adv. Energy Mater. 5 (2015). [7] J. Burschka, N. Pellet, S.J. Moon, R. Humphry-Baker, P. Gao, M.K. Nazeeruddin, M. Grätzel, Sequential deposition as a route to high-performance perovskitesensitized solar cells, Nature 499 (2013) 316–319. [8] X.Y. Chin, D. Cortecchia, J. Yin, A. Bruno, C. Soci, Lead iodide perovskite light-
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