Plasma-enhanced chemical vapor-deposited SiN and liquid-phase-deposited SiO2 stack double-layer anti-reflection films for multi-crystalline solar cells

Accepted Manuscript Plasma-enhanced chemical vapor-deposited SiN and liquid-phase-deposited SiO2 stack double-layer anti-reflection films for multi-crystalline solar cells Jing He, Yangchuan Ke PII:

S0749-6036(18)30917-0

DOI:

10.1016/j.spmi.2018.07.035

Reference:

YSPMI 5839

To appear in:

Superlattices and Microstructures

Received Date: 4 May 2018 Revised Date:

20 July 2018

Accepted Date: 20 July 2018

Please cite this article as: J. He, Y. Ke, Plasma-enhanced chemical vapor-deposited SiN and liquid-phase-deposited SiO2 stack double-layer anti-reflection films for multi-crystalline solar cells, Superlattices and Microstructures (2018), doi: 10.1016/j.spmi.2018.07.035. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT

Plasma-enhanced chemical vapor-deposited SiN and liquid-phase-deposited SiO2 stack double-layer anti-reflection films for multi-crystalline solar cells

RI PT

Jing He, Yangchuan Ke* CNPC Nano Chemistry Key Laboratory, College of Science,

China University of Petroleum-Beijing, 18 Fuxue Road, Changping,

SC

102249, Beijing, China

Abstract: We successfully fabricated a double-layer anti-reflection film for

M AN U

multi-crystalline silicon solar cells through liquid-phase deposition to deposit silicon dioxide (SiO2) film on a multi-crystalline silicon surface and plasma-enhanced chemical vapor deposition to deposit silicon nitride (SiN) film on a SiO2 film surface. The SiO2 film thicknesses were 10, 15, and 20 nm, and the SiN film thickness was 60 nm. The reflectance of the substrate markedly decreased as the double-layer film was deposited. Moreover, with different film thicknesses, the minimal values of the

TE D

reflectance were 4.91%, 2.75%, and 2.83% at the wavelengths of 609, 597, and 634 nm. The average reflection reached 6.92% when the thicknesses of SiO2 and SiN films were 20 and 60 nm in the wavelength range of 400–1100 nm. The minority carrier lifetimes of the multi-crystalline silicon substrates were 7.44, 7.21, and 7.27 µs

EP

at different film thicknesses. The short circuit current density and efficiency of the solar cell reached 34.52mA/cm2 and 16.56% when the thicknesses of the SiO2 and SiN films were 20 and 60 nm, respectively. Low reflectance and good cell

AC C

performance indicated that the double-layer film composed of SiO2 and SiN films were suitable for multi-crystalline silicon solar cells as the anti-reflection film. Keywords: LPD, Double-layer film, SiN/ SiO2, Anti-reflection, Solar cell

*

Corresponding author E-mail address: [email protected] (Yangchuan Ke)

ACCEPTED MANUSCRIPT

1. Introduction Anti-reflection films are required to reduce the optical loss of incident light for crystalline silicon solar cells so as to obtain high conversion efficiency because of the high refractive index of silicon substrate [1]. At present, anti-reflective coating (ARC)

RI PT

films for the crystalline silicon solar cell use silicon nitride (SiN) film, which is deposited using plasma-enhanced chemical vapor deposition (PECVD) [2]. The SiN film can provide effective surface and bulk passivation by generating hydrogen ions during PECVD and entering the wafers and neutralizing hanging bonds in silicon.

SC

However, single anti-reflection films present a narrow wavelength and range for incident light, and the high absorption in the UV region can reduce the short-circuit current density (Jsc) of solar cells

[3]

. Double-layer ARC films can address the above

M AN U

problem and decrease reflectance in a wide wavelength range [4-6].

Several transparent materials, such as SiO2, TiO2, Al2O3 and SiNx, are used as ARCs [7-10]. Among these ARC films, the SiO2 film exhibits numerous advantages, such as low refractive index, high thermal stability, good adhesion with the substrate, and good surface passivation to the substrate

[11, 12]

. As passivation films, thermal

oxide SiO2/PECVD-SiN stack films exhibit good passivation for silicon solar cells [13].

TE D

The double-layer ARC film, which was formed with SiN and SiO2 films, possessed good anti-reflection properties [14, 15]. Therefore, the double-layer film composed of SiN and SiO2 films offer broad application potential for use as anti-reflection film in solar cells.

[16]

EP

Numerous methods, such as evaporation

, PECVD[17] , electron cyclotron

resonance chemical vapor deposition [18], chemical vapor deposition [19], rapid thermal [20]

, sputtering

[21]

, and LPD, are currently being employed for growing

AC C

oxidation

anti-reflective films on silicon substrate [22]. Comparing with other ARC film growing methods, researchers found that LPD offer numerous advantages, including low cost, non-requirement of electrochemical methods and vacuum systems, low temperature, ease of mass production, and selective deposition

[23, 24]

. Moreover, the LPD system

does not require anodic equipment or an assisting energy source. Our previous works reported on the LPD of a single-layer SiO2 film on glass [25] , (100)-oriented Si

[26]

, GAN

methods, such as PECVD

[17]

[27, 28]

substrate, or SiO2 film deposited through other

, thermal oxide

[29-31]

, and sol–gel methods

[3, 32]

. In

this study, we invented a double-layer anti-reflectance film for multi-crystalline silicon surface with LPD-SiO2 film and PECVD-SiN film and investigated the

ACCEPTED MANUSCRIPT anti-reflection and passivation properties of the double film. Solar cells with double ARC films were produced, and the electrical properties of the solar cells were investigated.

2. Experiment Details

RI PT

p-Type multi-crystalline silicon wafers with wafer thickness of 200 µm ± 20 µm, the area of 156 × 156 mm2, and the resistivity of 1–3 Ω·cm, were used as substrate. Figure 1 shows the fabrication method of the multi-crystalline solar cell.

Figure 1a shows the fabrication method of the multi-crystalline silicon solar cell.

SC

The silicon wafer was texturized in a mixture solution of hydrofluoric acid (HF) and nitric acid at 13 °C ± 2 °C. The wafer was doped in phosphorus by using phosphorous oxychloride in a tube furnace at 900 °C to form a p–n junction. After doping, the edge

M AN U

of the silicon wafer was etched by CF4/O2 plasma, and phosphorous silicate glass was removed by etching in diluted HF (5% by volume) solution. The sheet resistance of the silicon was 70 Ω/□, which was measured using a four-point probe. Then, the SiO2 film was deposited through LPD on the silicon wafer, and the SiN film was deposited on the SiO2 film through PECVD. After the anti-reflection film was deposited, the back electrode, back field, and front electrode were formed by screen-printing method

TE D

with Al and Ag pastes. Finally, the cell was co-fired and its performance was tested. Figure 2 shows the schematic of the multi-crystalline solar cell. The double-layer anti-reflection films were composed of SiO2 and SiN films. The SiO2 film was deposited through LPD. Figure 3a shows the schematic of the LPD

EP

system. The deposition system involved (1) a heating system, (2) a magnetic stirring system, and (3) a temperature monitoring system. Prior to deposition, the silicon

AC C

wafer must be treated with diluted HF at 40 °C to remove the native oxide and generate Si–H surface bonds. The Si–H bonds react with the H2O molecule in deionized water to produce hydroxyl bonds on the substrate surface. Figure 3b shows the flow chart of the LPD-SiO2 process at a deposition temperature of 40 °C. The starting solution was a commercial 35% H2SiF6 stirred with silica powder to form SiO2 saturated hydrofluorosilicic acid solution. Then, the saturated H2SiF6 solution was diluted in deionized water to achieve the desired H2SiF6 concentration of 1.25 M. We controlled the thickness of the LPD-SiO2 film from 10 nm to 20 nm. After the SiO2 film was deposited, a 60 nm-thick SiN film was deposited on the SiO2 film through PECVD. The surface morphologies and X-ray spectrometry (EDS) of double

ACCEPTED MANUSCRIPT anti-reflection films were investigated by using field-emission scanning electron microscopy (SEM, SU8010). The surface reflectance of double anti-reflection films was examined by a UV–vis–NIR spectrophotometer (Varian Cary 5000) equipped with an integrating sphere detector in a wavelength range of 400–1100 nm. The minority carrier lifetime was determined by a microwave photoconductive decay

RI PT

(µ-PCD, Semilab WT-2000). The current–voltage characteristic curve and electrical parameters of the solar cells were obtained under AM 1.5 illumination conditions.

3. Results and Discussion

SC

The basic chemical reaction of LPD-SiO2 is represented as follows:

(1)

M AN U

H 2 SiF6 + 2 H 2O ⇌ 6 HF + SiO2

In Equation (1), H2SiF6 is hydrolyzed to SiO2 and HF. SiO2 film was successfully deposited on the multi-crystalline silicon substrate surface through LPD. Figure 4 shows the surface morphology of the LPD-SiO2 film on the Si substrate, with Figures 4a and 4b respectively showing the top-view and cross-sectional image at a

TE D

H2SiF6 concentration of 1.25 M. Figure 4 exhibits the uniform coverage of the approximately 23 nm-thick LPD-SiO2 film on the Si substrate and flat interface between LPD-SiO2 and the Si substrate.

After the SiO2 film was deposited, the SiN film was successfully deposited on

EP

the LPD-SiO2 film surface through PECVD. Figure 5 shows the surface morphology of the double-layer anti-reflection film on the multi-crystalline silicon wafer. Figures 5a and 5b respectively show the top-view and cross-sectional images of the

AC C

double-layer anti-reflection film. Figures 5a and 5b shows a double-layer film on the multi-crystalline silicon substrate. The LPD-SiO2 film on the Si substrate presented uniform coverage and a flat interface between LPD-SiO2 and the Si substrate. The SiN film uniformly covered the LPD-SiO2 film, and the thickness of the double-layer film was approximately 79.5 nm. Elemental analysis was conducted to determine the composition of the prepared SiN/SiO2 anti-reflection film on the multi-crystalline silicon substrate surface. Figure 6 shows the EDS spectra of the SiN/SiO2 anti-reflection film (Figure 5). The film thickness of SiO2 and SiN films were 23 and 56.5 nm, respectively. Table 1 presents the elemental composition of the double film. As indicated in Figure 6 and Table 1,

ACCEPTED MANUSCRIPT the double-layer film mainly contained Si, oxygen, and nitrogen at 80.76, 1.67, and 17.57 wt.% , respectively. Si content included Si from the multi-crystalline silicon substrate because of the relatively low thickness of the SiN/SiO2 film. The anti-reflection property of the double-layer film was evaluated based on the obtained reflectance spectra of the single LPD-SiO2 film and the SiN/SiO2 reflectance

curves

of

the

acid-textured

RI PT

double-layer anti-reflection films at different thicknesses. Figure 7 shows the multi-crystalline

silicon

wafer,

multi-crystalline silicon wafer with single layer LPD–SiO2 film on the surface, multi-crystalline silicon wafer with single layer PECVD-SiN film on the surface, and multi-crystalline silicon wafer with PECVD-SiN/ LPD-SiO2 double-layer film on the

SC

surface. The thicknesses of single layer LPD-SiO2 films were 10, 15, and 20 nm, the thickness of the single layer SiN film were 70, 75 and 80nm, and the thicknesses of

M AN U

double-layer anti-reflection films are shown in Table 2.

Figure 7 shows that the reflectance of the silicon wafer with LPD-SiO2 film was lower than that of acid-textured wafer, and the reflection decreased with increasing SiO2 film thickness. Following the deposition of the PECVD-SiN ARC film on the LPD–SiO2 film, the reflectance of the silicon wafer evidently decreased in the wavelength range of 400–1100 nm. At the wavelength range of 400-700 nm, the

TE D

reflectance of the silicon wafer with double-layer PECVD-SiN/LPD-SiO2 film on the surface is obviously lower than that of silicon wafer with same thickness single-layer SiN film on the surface. The minimal reflectance values of 4.91%, 2.75%, and 2.83% can be obtained at the wavelengths of 609, 597 and 634 nm, respectively.

EP

Table 3 shows the average reflectance of the textured silicon, silicon with single-layer SiN film, and silicon with double-layer films 1, 2, and 3 , and the average reflectance

(Ra)

can

be

defined

by

Equation

(2),

where

R(λ)

is

the

AC C

wavelength-dependent reflectance, and N(λ) is the solar flux under AM 1.5 standard conditions. The Ra of the textured silicon wafer in the range of 400–1100 nm was 28.12%. The Ra of the silicon wafer with 70nm, 75nm and 80nm single-layer SiN film on the surface were 12.11%, 11.55% and 11.05%, respectively, in the range of 400–1100 nm. The Ra of the double-layer film 1 with 60 nm SiN and 10 nm SiO2 films was 9.03% in the range of 400–1100 nm. Double-layer film 2, with 60 nm SiN and 15 nm SiO2 film, presented an Ra of 6.98% in the range of 400–1100 nm. The Ra of the double-layer film 3 with 60 nm SiN and 20 nm SiO2 film was 6.92% in the range of 400–1100 nm. The Ra of the multi-crystalline silicon wafer with the single layer SiN film, single layer Al2O3 film and single layer TiO2 film on the surface were

ACCEPTED MANUSCRIPT 10.25%

[33]

, 11.2% (the calculate wavelength range is 400-900nm)

calculate wavelength range is 400-1000nm)

[35]

[34]

and 9% (the

, respectively. It’s all higher than the

Ra of the multi-crystalline silicon wafer which was used double-layer PECVD-SiN/ LPD-SiO2 film as the anti-reflectance film. These results indicate that double-layer ARC film can effectively decrease light reflection and increase light absorption in a

RI PT

broad wavelength region. At the same time, in the wavelength range of 400-800nm, the multi-crystalline silicon wafer with 20nm LPD SiO2 film on the surface has a lower reflectance than the wafer with same thickness PECVD SiO2 film on the surface[36], and the LPD method has the advantages of high deposition rate and low cost compared with PECVD method[37]. So, the antireflective property of the SiN/ deposition

methods,

such

as

PECVD-SiO2/PECVD-SiN

1100

∫ 400

[1]

.

M AN U

anti-reflection films for crystalline solar cells

Ra =

SC

SiO2 double layer film is comparable with those of films prepared using other vacuum

R ( λ ) N (λ ) d λ /

1100

∫

N (λ ) d λ

double-layer

as

(2)

400

The anti-reflection film on the multi-crystalline silicon wafer not only reduces

TE D

the reflectance of the silicon substrate to sunlight but also exerts a passivation effect on the substrate. The passivation property was proven by the minority carrier lifetime. Figure 8 show the minority carrier lifetime values of a single LPD-SiO2 film and double-layer ARC film. It’s shown in Figure 8, the minority carrier lifetime values

EP

were 3.78µs, 6.26µs, 6.54µs and 6.76µs when the thickness of the LPD SiO2 film on the silicon wafer were 0nm, 10nm, 15nm and 20nm, respectively. The minority carrier

AC C

lifetime values were 3.78µs, 7.44µs, 7.21µs and 7.27µs when the thickness of the PECVD-SiN/ LPD-SiO2 double-layer film on the silicon wafer were 0nm, 70nm, 75nm and 80nm, respectively. It’s shown that, after the SiO2 film was deposited on the multi-crystalline silicon surface, the minority carrier lifetime values of the silicon wafer were evidently improved, and the minority carrier lifetime value was increased as the SiO2 film thickness increased. This finding suggests that LPD-SiO2 film on the multi-crystalline wafer surface enhances passivation performance. After the SiN film was deposited using PECVD on the LPD-SiO2 film surface, the lifetime value of the minority carrier exceeded that of the silicon wafer with a single-layer LPD-SiO2 film on the surface, this could be because the hydrogen atom generated during PECVD enters the silicon and passivates impurities and defects. The minority carrier lifetime

ACCEPTED MANUSCRIPT tested results indicate that the double layer anti-reflection film possesses good passivation performance for the multi-crystalline silicon wafer and demonstrates the applicability of the material in multi-crystalline solar cells as anti-reflection and passivation films [38, 39]. Multi-crystalline solar cells with different thicknesses of SiN/SiO2 (Table 2) as

RI PT

anti-reflection films were fabricated. Figure 9 shows the current–voltage curve of the solar cell with the anti-reflection double-layer films 1, 2, and 3. The solar cell with the anti-reflection double-layer film 3 with film thicknesses of 20 (LPD-SiO2) and 60 nm (PECVD-SiN film) exhibited the best performance.

Table 4 lists the electrical parameters of solar cells with double-layer films 1, 2,

SC

and 3 and a single 80 nm-thick SiN layer deposited using PECVD as anti-reflection films. The solar cell with single SiN layer showed lower cell efficiency compared

M AN U

with cells with the double anti-reflection film. The Jsc of the solar cell with the single SiN layer film was lower than that of solar cells with double-layer anti-reflection films because the double-layer anti-reflection film can increase the absorption of the silicon substrate. The Jsc of the solar cell increased with SiO2 film thickness increased. The solar cell with double-layer film 3, which was composed of 20 nm SiO2 film and 60 nm SiN film, presented an Jsc of 34.52 mA/cm2, which was almost 0.99 mA/cm2

TE D

and 0.29 mA/cm2 higher than those of solar cells with double-layer films 1 and 2, respectively. This finding is due to the decreased reflection of the double-layer ARC film with increasing SiO2 film thickness, and the average anti-reflection of double-layer film 3, which was composed of 20 nm SiO2 film and 60 nm SiN film,

EP

was 6.92% in the wavelength range of 400–1100 nm. Moreover, the luminous flux entering the silicon and Jsc both increased. The open circuit voltage (Voc) and fill factor (FF) of the solar cell with the anti-reflection film of double-layer films 1, 2, and

AC C

3 were similar. The efficiencies of the solar cell with different anti-reflection layers were 15.9%, 16.32%, and 16.56%. The efficiency of the solar cell used double-layer film as the anti-reflection film was higher than the multi-crystalline silicon solar cells which were used other materials as the anti-reflection film, such as SiO2/TiO2 double layer film (11.21%)

[36]

, single layer chemical vapor deposition SiN film (15.7%) [40],

single layer Al2O3 film (14.8%)

[41]

and Indium oxide nanowire (15.28%)

[42]

. High

solar cell conversion efficiency indicated that the double-layer film with LPD-SiO2 and PECVD film was suitable for multi-crystalline solar cells.

ACCEPTED MANUSCRIPT

4. Conclusion Anti-reflection films can effectively reduce sunlight loss, illuminate the solar cell substrate surface, and improve the conversion efficiency of solar cells. In addition, anti-reflection films exert a passivation effect, improving the minority carrier lifetime on the solar cell surface and its internals. Single anti-reflection films can improve the

RI PT

sunlight absorption of the substrate in a narrow wavelength range, whereas the double-layer anti-reflection films can reduce sunlight loss within a wide wavelength number range. This study reports that double-layer films composed of LPD-SiO2 and PECVD-SiN films are successfully prepared on the multi-crystalline silicon surface as

SC

anti-reflection films for multi-crystalline solar cells. The reflectance and minority carrier lifetime are investigated at different double-layer anti-reflection film thicknesses. The reflection of the double-layer film is affected by film thickness, and

M AN U

the reflectivity of the double-layer film decreases with increasing film thickness. The average reflectance of the silicon wafer with 20 nm SiO2 film and 60 nm SiN film on the surface was 6.92% in the wavelength range of 400–1100 nm. The minority carrier lifetime of the multi-crystalline silicon substrate markedly increases after the deposition of the double-layer film on the substrate surface. The short-circuit current density of the solar cell with the double anti-reflection film increases as the SiO2 film

TE D

thickness increases. The efficiency of the solar cell with the double anti-reflection film can reach 16.56% at the LPD-SiO2 film thickness of 20 nm. This finding indicates that the double-layer film comprising LPD-SiO2 and PECVD-SiN films is

AC C

EP

suitable for use in multi-crystalline solar cells as the anti-reflection film.

ACCEPTED MANUSCRIPT

Acknowledgments The authors acknowledge the financial support from the National Natural Science Foundation of China (Grant No. 51674270), the National Major Project (Grant No. 2017ZX05009–003), the Major project of the National Natural Science Foundation of China (No.51490650), and the Foundation for Innovative Research

AC C

EP

TE D

M AN U

SC

RI PT

Groups of the National Natural Science Foundation of China (Grant: No. 51521063).

ACCEPTED MANUSCRIPT

References [1] J. Kim, J. Park, J.H. Hong, S.J. Choi, G.H. Kang, G.J. Yu, N.S. Kim, H.E. Song, Double antireflection coating layer with silicon nitride and silicon oxide for crystalline silicon solar cell, Journal of Electroceramics, 30 (2013) 41-45. [2] X. Wu, Z. Zhang, Y. Liu, X. Chu, Y. Li, Process parameter selection study on

RI PT

SiNx:H films by PECVD method for silicon solar cells, Solar Energy, 111 (2015) 277-287.

[3] A. Jannat, Z.Y. Li, M.S. Akhter, O.B. Yang, Variation in the Optical Properties of the SiC-SiO2 Composite Antireflection Layer in Crystalline Silicon Solar Cells by

SC

Annealing, Journal of Electronic Materials, 46 (2017) 6357-6366.

[4] H. Kanda, A. Uzum, N. Harano, S. Yoshinaga, Y. Ishikawa, Y. Uraoka, H. Fukui, T.

M AN U

Harada, S. Ito, Al2O3/TiO2 double layer anti-reflection coating film for crystalline silicon solar cells formed by spray pyrolysis, Energy Science & Engineering, 4 (2016) 269-276.

[5] A. Siva Rama Krishna, S.L. Sabat, M. Ghanashyam Krishna, The design of broad band anti-reflection coatings for solar cell applications, The European Physical Journal Applied Physics, 77 (2017) 10301.

TE D

[6] D.S. Wuu, C.C. Lin, C.N. Chen, H.H. Lee, J.J. Huang, Properties of double-layer Al2O3/TiO2 antireflection coatings by liquid phase deposition, Thin Solid Films, 584 (2015) 248-252.

[7] S.H. Jeong, J. K. Kim, B. S. Kim, S. H. Shim, B. T. Lee, Characterization of SiO2

EP

and TiO2 films prepared using rf magnetron sputtering and their application to anti-reflection coating, Vacuum, 76 (2004) 507-515. [8] T. Ishiguro, T. Hori, Z. Qiu, Antireflective coating using aluminum hydroxide

AC C

formed by hydrothermal treatment of sputtered aluminum films, Journal of Applied Physics, 106 (2009) 023524. [9] Y. Wang, B. Shao, Z. Zhang, L. Zhuge, X. Wu, R. Zhang, Broadband and omnidirectional antireflection of Si nanocone structures cladded by SiN film for Si thin film solar cells, Optics Communications, 316 (2014) 37-41. [10] J.J. Huang, Y.T. Lee, Self-cleaning and antireflection properties of titanium oxide film by liquid phase deposition, Surface and Coatings Technology, 231 (2013) 257-260. [11] C.J. Huang, Enhancement of metal–semiconductor barrier height with superthin silicon dioxide films deposited on gallium arsenide by liquid phase deposition, Journal of Applied Physics, 89 (2001) 6501.

ACCEPTED MANUSCRIPT [12] K.C. Kim, Effective graded refractive-index anti-reflection coating for high refractive-index polymer ophthalmic lenses, Materials Letters, 160 (2015) 158-161. [13] A.J.M. van Erven, R.C.M. Bosch, M.D. Bijker, Textured silicon surface passivation by high-rate expanding thermal plasma deposited SiN and thermal SiO2/SiN stacks for crystalline silicon solar cells, Progress in Photovoltaics: Research

RI PT

and Applications, 16 (2008) 615-627. [14] B.G. Priyadarshini, A.K. Sharma, Design of multi-layer anti-reflection coating for terrestrial solar panel glass, Bulletin of Materials Science, 39 (2016) 683-689.

[15] H. Ghosh, S. Mitra, H. Saha, S.K. Datta, C. Banerjee, Argon plasma treatment of Science and Engineering: B, 215 (2017) 29-36.

SC

silicon nitride (SiN) for improved antireflection coating on c-Si solar cells, Materials [16] S.J. Patil, K.C. Mohite, A.B. Mandale, M.G. Takwale, S.A. Gangal,

M AN U

Characterization of ‘ARE’ deposited silicon nitride films and their feasibility as antireflection coating, Surface and Coatings Technology, 200 (2005) 2058-2064. [17] R.G. Andosca, W.J. Varhue, E. Adams, Silicon dioxide films deposited by electron cyclotron resonance plasma enhanced chemical vapor deposition, Journal of Applied Physics, 72 (1992) 1126.

[18] C.J. Huang, Quality optimization of liquid phase deposition SiO2 films on silicon,

TE D

Japanese Journal of Applied Physics, 41 (2002) 4622-4625.

[19] K.W. Lee, J.S. Huang, Y.L. Lu, F.M. Lee, H.C. Lin, J.J. Huang, Y.H. Wang, Liquid-phase-deposited SiO2 on AlGaAs and its application, Semiconductor Science and Technology, 2011, pp. 055006.

EP

[20] S.Y. Yoon, Y.S. Park, J.S. Lee, Local liquid phase deposition of silicon dioxide on hexagonally close-packed silica beads, Langmuir, 31 (2015) 249-253. [21] Y. Wang, X. Cheng, Z. Lin, C. Zhang, H. Xiao, F. Zhang, S. Zou, Analysis of

AC C

IBAD silicon oxynitride film for anti-reflection coating application, Journal of Non-Crystalline Solids, 333 (2004) 296-300. [22] G.H. Yang, J.D. Hwang, C.H. Lan, C.M. Chan, H.Z. Chen, S.J. Chang, Indium– tin-oxide metal–insulator–semiconductor GaN ultraviolet photodetectors using liquid-phase-deposition oxide, Japanese Journal of Applied Physics, 46 (2007) 5119-5121. [23] S. Iizuka, S. Ooka, A. Nakata, M. Mizuhata, S. Deki, Development of fabrication process for metal oxide with nano-structure by the liquid-phase infiltration (LPI) method, Electrochimica Acta, 51 (2005) 802-808. [24] S. Deki, S. Iizuka, A. Horie, M. Mizuhata, A. Kajinami, Liquid-phase infiltration

ACCEPTED MANUSCRIPT (LPI) process for the fabrication of highly nano-ordered materials, Chemistry of Materials, 16 (2004) 1747-1750. [25] Y. Lv, Z. Fu, B. Yang, J. Xu, M. Wu, C. Zhu, Y. Zhao, Preparation N–F-codoped TiO2 nanorod array by liquid phase deposition as visible light photocatalyst, Materials Research Bulletin, 46 (2011) 361-365. silicon, Japanese Journal of Applied Physics, 41 (2002) 4622.

RI PT

[26] H. Chien-Jung, Quality optimization of liquid phase deposition SiO2 films on [27] Y.S. Lee, S. Lee, J.D. Kwon, J.H. Ahn, J.S. Park, Silicon oxide film deposited at room temperatures using high-working-pressure plasma-enhanced chemical vapor deposition: effect of O2 flow rate, Ceramics International, 43 (2017) 10628-10631.

SC

[28] J. Fu, H. Shang, Z. Li, W. Wang, D. Chen, Thermal annealing effects on the stress stability in silicon dioxide films grown by plasma-enhanced chemical vapor

M AN U

deposition, Microsystem Technologies, 23 (2016) 2753-2757.

[29] N. Balaji, C. Park, S. Chung, M. Ju, J. Raja, J. Yi, Effects of low temperature anneal on the interface properties of thermal silicon oxide for silicon surface passivation, Journal of Nanoscience and Nanotechnology, 16 (2016) 4783-4787. [30] F. Cao, L. Tang, Y. Li, A.P. Litvinchuk, J. Bao, Z. Ren, A high-temperature stable spectrally-selective solar absorber based on cermet of titanium nitride in SiO2

TE D

deposited on lanthanum aluminate, Solar Energy Materials and Solar Cells, 160 (2017) 12-17.

[31] T. Matsumoto, H. Nakajima, D. Irishika, T. Nonaka, K. Imamura, H. Kobayashi, Ultrathin SiO2 layer formed by the nitric acid oxidation of Si (NAOS) method to

EP

improve the thermal-SiO2/Si interface for crystalline Si solar cells, Applied Surface Science, 395 (2017) 56-60.

[32] Y. Yuan, G.H. Yan, S.H. Huang, R.J. Hong, Preparation of hydrophobic

AC C

SiO2/PMHS sol and ORMOSIL antireflective films for solar glass cover, Solar Energy, 130 (2016) 1-9.

[33] A. El amrani, I. Menous, L. Mahiou, R. Tadjine, A. Touati, A. Lefgoum, Silicon nitride film for solar cells, Renewable Energy, 33 (2008) 2289-2293. [34] Y. Jiang, H. Shen, W. Yang, C. Zheng, Q. Tang, H. Yao, A. Raza, Y. Li, C. Huang, Passivation properties of alumina for multicrystalline silicon nanostructure prepared by spin-coating method, Applied Physics A, 124 (2018). [35] S. Sali, S. Kermadi, L. Zougar, B. Benzaoui, N. Saoula, K. Mahdid, F. Aitameur, M. Boumaour, Nanocrystalline proprieties of TiO2 thin film deposited by ultrasonic spray pulverization as an anti-reflection coating for solar cells applications, Journal of

ACCEPTED MANUSCRIPT Electrical Engineering, 68 (2017). [36] P. Panek, K. Drabczyk, A. Focsa, A. Slaoui, A comparative study of SiO2 deposited by PECVD and thermal method as passivation for multicrystalline silicon solar cells, Materials Science and Engineering: B, 165 (2009) 64-66. [37] Y.J.L. C.C. Yeh, S.K. Lin, Y.H. Wang, S.F. Chung, L.M. Huang, T.C. Wen,

RI PT

Plasma treatment on plastic substrates for liquid-phase-deposited SiO2, Journal of Vacuum Science & Technology B, 25 (2007) 5.

[38] B. Macco, J. Melskens, N.J. Podraza, K. Arts, C. Pugh, O. Thomas, W.M.M. Kessels, Correlating the silicon surface passivation to the nanostructure of low-temperature a-Si:H after rapid thermal annealing, Journal of Applied Physics, 122

SC

(2017) 035302.

[39] P.W. Sze, K.L. Chen, C.J. Huang, C.C. Kang, T.H. Meen, Effect of passivation

M AN U

layers by liquid phase deposition (LPD) on moisture and oxygen protection for flexible organic light-emitting diode (FOLED), Microelectronic Engineering, 148 (2015) 17-20.

[40] V. Verlaan, C.H.M. Werf, Z.S. Houweling, I.G. Romijn, A.W. Weeber, H.F.W. Dekkers, H.D. Goldbach, R.E.I. Schropp, Multi-crystalline Si solar cells with very fast deposited (180 nm/min) passivating hot-wire CVD silicon nitride as antireflection

TE D

coating, Progress in Photovoltaics: Research and Applications, 15 (2007) 563-573. [41] H.Y. Chen, H.L. Lu, L. Sun, Q.H. Ren, H. Zhang, X.M. Ji, W.J. Liu, S.J. Ding, X.F. Yang, D.W. Zhang, Realizing a facile and environmental-friendly fabrication of high-performance

multi-crystalline

silicon

solar

cells

by

employing

ZnO

EP

nanostructures and an Al2O3 passivation layer, Scientific reports, 6 (2016) 38486. [42] Y.C. Wang, C.Y. Chen, C.W. Kuo, T.M. Kuan, C.Y. Yu, I.C. Chen, Low-temperature grown indium oxide nanowire-based antireflection coatings for

AC C

multi-crystalline silicon solar cells, physica status solidi (a), 213 (2016) 2259-2263.

ACCEPTED MANUSCRIPT

M AN U

SC

RI PT

Figures

AC C

EP

TE D

Fig. 1

Fig. 2

M AN U

SC

Fig. 3

RI PT

ACCEPTED MANUSCRIPT

Fig. 5

AC C

EP

TE D

Fig. 4

Fig. 6

TE D

M AN U

SC

Fig. 7

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

Fig.8

Fig. 9

ACCEPTED MANUSCRIPT

Figure captions Fig. 1 Fabrication process of the multi-crystalline solar cell. Fig. 2 Schematic of the multi-crystalline solar cell. Fig. 3 (a) Schematic of deposition system for LPD-SiO2 and (b) flow chart for front-to-end LPD-SiO2 process.

RI PT

Fig. 4 SEM of LPD-SiO2 film: (a) top view of the LPD-SiO2 film, (b) cross-sectional image of the LPD-SiO2 film.

Fig. 5 SEM of the double anti-reflection film: (a) top view of the double film, (b) cross-sectional image of the double film.

SC

Fig. 6 EDS result of the SiN/SiO2 double film.

Fig. 7 Reflectance spectra of the acid textured wafer, single-layer LPD-SiO2 film, single layer PECVD SiN film with different thicknesses and the double-layer SiN/SiO2 film with different film

M AN U

thicknesses.

Fig.8 Minority carrier lifetime of the single LPD–SiO2 film with different thicknesses and double-layer SiN/SiO2 ARC film with different film thicknesses.

Fig. 9 Current–voltage curves of the solar cells with the anti-reflection film of double-layer films 1,

AC C

EP

TE D

2, and 3.

ACCEPTED MANUSCRIPT

Tables Table 1 Intensity

Atomic

Content

(c/s)

%

wt.%

O

2.61

2.47

1.67

N

11.28

29.62

17.57

Si

2919.62

67.91

80.76

RI PT

Element

Samples

LPD-SiO2 film

Double-layer film 1

10 nm

Double-layer film 2

15 nm

SC

Table 2

PECVD-SiN film

M AN U

60 nm

Double-layer film 3

20 nm

60 nm 60 nm

Table 3

Samples

Average reflectance

TE D

(%)

28.12

Double-layer film 1

9.03

Double-layer film 2

6.98

Double-layer film 3

6.92

EP

Acid texture

12.11

Single-layer SiN 75nm

11.55

Single-layer SiN 80nm

11.05

AC C

Single-layer SiN 70nm

Table 4

Voc (V)

Jsc (mA/cm2)

FF (%)

Eff (%)

Rsh (Ω)

Rs (mΩ)

Double-layer 1

0.606

33.53

78.87

15.90

32.60

1.40

Double-layer 2

0.611

34.23

78.74

16.32

35.35

1.63

Double-layer 3

0.609

34.52

78.64

16.56

21.02

1.21

Single SiN layer

0.604

33.12

78.66

15.61

21.95

1.38

ACCEPTED MANUSCRIPT

Table captions Table 1 Elemental content of the EDS test Table 2 Thickness of the double anti-reflection films Table 3 Average reflectance of multi-crystalline silicon wafer with and without anti-reflection film

AC C

EP

TE D

M AN U

SC

RI PT

Table 4 Experimental parameters of solar cells

ACCEPTED MANUSCRIPT

Highlights

EP

TE D

M AN U

SC

RI PT

LPD SiO2 film is deposit on the multi-crystalline silicon surface. PECVD SiN film is deposit on the LPD SiO2 film. SiN/ SiO2 double layer film as the anti-reflection film for the solar cell.

AC C