Current Photovoltaic Research

Korea Photovoltaic Society (한국태양광발전학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Glass Texturing Structure on the Module Efficiency of Heterojunction Silicon Solar Cells

  • Park, Hyeongsik (College of Information and Communication Engineering, Sungkyunkwan University (SKKU)) ;
  • Lee, Yoo Jeong (School of Electronics, Telecommunications and Computer Engineering, #76, Korea Aerospace University (KAU)) ;
  • Shin, Myunghun (School of Electronics, Telecommunications and Computer Engineering, #76, Korea Aerospace University (KAU)) ;
  • Lee, Youn-Jung (College of Information and Communication Engineering, Sungkyunkwan University (SKKU)) ;
  • Lee, Jaesung (School of Electronics, Telecommunications and Computer Engineering, #76, Korea Aerospace University (KAU)) ;
  • Park, Changkyun (Crystalline Part, JUSUNG Engineering Co. Ltd.) ;
  • Yi, Junsin (College of Information and Communication Engineering, Sungkyunkwan University (SKKU))
  • Received : 2018.09.18
  • Accepted : 2018.10.15
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

A glass-texturing technique was developed for photovoltaic (PV) module cover glass; periodic honeycomb textures were formed by using a conventional lithography technique and diluted hydrogen fluoride etching solutions. The etching conditions were optimized for three different types of textured structures. In contrast to a flat glass substrate, the textured glasses were structured with etched average surface angles of $31-57^{\circ}$, and large aspect ratios of 0.17-0.47; by using a finite difference time-domain simulation, we show that these textured surfaces increase the amount of scattered light and reduce reflectance on the glass surface. In addition, the optical transmittance of the textured glass was markedly improved by up to 95% for wavelengths ranging from 400 to 1100 nm. Furthermore, applying the textured structures to the cover glass of the PV module with heterojunction with intrinsic thin-layer crystalline silicon solar cells resulted in improvements in the short-circuit current density and module efficiency from 39 to $40.2mA/cm^2$ and from 21.65% to 22.41%, respectively. Considering these results, the proposed method has the potential to further strengthen the industrial and technical competitiveness of crystalline silicon solar cells.

Keywords

TOGBCQ_2018_v6n4_102_f0001.png 이미지

Fig. 2. Aspect ratio as a function of structural angle for the various types of textured PV mini-module cover glass (Etch-1, Etch-2, and Etch-3)

TOGBCQ_2018_v6n4_102_f0002.png 이미지

Fig. 3. FDTD simulation and measurement results for Etch-1, Etch-2, and Etch-3. (a) Spectral transmittance and (b) average transmittance for the wavelength range of 400 to 1100 nm, and (c) FDTD simulation images of the light wave propagation occurring immediately after light reaches the textured surface

TOGBCQ_2018_v6n4_102_f0003.png 이미지

Fig. 4. Comparison of current density as a function of applied voltage (I-V curves) for PV modules with a non-textured cover glass and Etch-1-, Etch-2-, and Etch-3-type cover glasses

TOGBCQ_2018_v6n4_102_f0004.png 이미지

Fig. 5. EQE curves for PV modules with a non-textured cover glass and an Etch-2-type textured cover glass

TOGBCQ_2018_v6n4_102_f0005.png 이미지

Fig. 1. (a) Ultraviolet photolithography process for cover glass texturing, (b) types of textured glasses, (c) layers of HIT Si solar cell, and (d) module structure including the textured cover glass and HIT Si solar cells

Table 1. Glass texturing structures according to chemical etching conditions, and structural parameters (aspect ratio) and haze values (HT)

TOGBCQ_2018_v6n4_102_t0001.png 이미지

Table 2. Comparison of I-V and structural results of PV modules with different texturing glass

TOGBCQ_2018_v6n4_102_t0002.png 이미지

References

  1. K. Yoshikawa, H. Kawasaki, W. Yoshida, T. Irie, K. Konishi, K. Nakano, T. Uto, D. Adachi, M. Kanematsu, H. Uzu, J. Yamamoto, "Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26%", Nat. Energy, Vol. 2, 17032, 2017. https://doi.org/10.1038/nenergy.2017.32
  2. C. Battaglia, A. Cuevas, S. De Wolf, "High-efficiency crystalline silicon solar cells: status and perspectives", Energy Environ. Sci., Vol. 9, pp. 1552-1576, 2016. https://doi.org/10.1039/C5EE03380B
  3. F. Mavromatakis, F. Vignola, B. Marion, "Low irradiance losses of photovoltaic modules", Sol. Energy, Vol. 157, pp. 496-506, 2017. https://doi.org/10.1016/j.solener.2017.08.062
  4. P. G. Piedra, L. R. Llanza, H. Moosmuller, "Optical losses of photovoltaic modules due to mineral dust deposition: Experimental measurements and theoretical modeling", Sol. Energy, Vol. 164, pp. 160-173, 2018. https://doi.org/10.1016/j.solener.2018.02.030
  5. B. Geetha Priyadarshini, A. K. Sharma, "Design of multi-layer anti-reflection coating for terrestrial solar panel glass", Bull. Mater. Sci., Vol. 39, No. 3, pp. 683-689, 2016. https://doi.org/10.1007/s12034-016-1195-x
  6. D. Huh, J.-H. Shin, M. Byun, S. Son, P.-H. Jung, H.-J. Choi, Y.-D. Kim, H. Lee, "Analysis of long-term monitoring data of PV module with SiOx-based anti-reflective patterned protective glass", Sol. Energy Mater. Sol. Cells, Vol. 170, pp. 33-38, 2017. https://doi.org/10.1016/j.solmat.2017.05.031
  7. R. Bohme, K. Zimmer, "Low roughness laser etching of fused silica using an adsorbed layer", Appl. Surf. Sci., Vol. 239, pp. 109-116, 2004. https://doi.org/10.1016/j.apsusc.2004.05.095
  8. F. Chen, H. Liu, Q. Yang, X. Wang, C. Hou, H. Bian, W. Liang, J. Si, X. Hou, "Maskless fabrication of concave microlens arrays on silica glasses by a femtosecond-laser-enhanced local wet etching method", Opt. Express, Vol. 18, No. 19, pp. 20334-20343, 2010. https://doi.org/10.1364/OE.18.020334
  9. C. Xie, X. Li, K. Liu, M. Zhu, R. Qiu, Q. Zhou, "Direct writing of sub-wavelength ripples on silicon using femtosecond laser at high repetition rate", Appl. Surf. Sci., Vol. 360, pp. 896-903, 2016. https://doi.org/10.1016/j.apsusc.2015.11.082
  10. C. Battaglia, C. M. Hsu, K. Soderstrom, J. Escarre, C. Ballif, "Light trapping in solar cells: can periodic beat random?", ACS Nano, Vol. 6, No. 3., pp. 2790-2797, 2012. https://doi.org/10.1021/nn300287j
  11. P. Spinelli, V. E. Ferry, J. V. D. Groep, M. V. Lare, A. Polman, "A Plasmonic Light Trapping in Thin-Film Si Solar Cells", J. Opt., Vol. 14, No. 2, pp. 024002-024013, 2012. https://doi.org/10.1088/2040-8978/14/2/024002
  12. G. Kumaravelu, M. M. Alkaisi, A. Bittar, D. Macdonald, J. Zhao, "Damage studies in dry etched textured silicon surfaces", Current. Appl. Phys., Vol. 4, No. 2-4, pp. 108-110, 2004. https://doi.org/10.1016/j.cap.2003.10.008
  13. M. Tucci, E. Salurso, F. Roca, F. Palma, "Dry cleaning process of crystalline silicon surface in a-Si:H/c-Si heterojunction for photovoltaic applications", Thin Solid Films, Vol. 403-404, pp. 307-311, 2002. https://doi.org/10.1016/S0040-6090(01)01645-5
  14. J. Yoo, K. Kim, M. Thamilselvan, N. Lakshminarayn, Y. K. Kim, J. H. Lee, K. J. Yoo, J. Yi, "RIE texturing optimization for thin c-Si solar cells in $SF_6/O_2$ plasma", J. Phys. D: Appl. Phys., Vol. 41, No. 12, 125205, 2008. https://doi.org/10.1088/0022-3727/41/12/125205
  15. A. Hongsingthong, T. Krajangsang, I. A. Yunaz, S. Miyajima, M. Konagai, "ZnO Films with Very High Haze Value for Use as Front Transparent Conductive Oxide Films in Thin-Film Silicon Solar Cells", Appl. Phys. Express, Vol. 3, pp. 051102-051111, 2010. https://doi.org/10.1143/APEX.3.051102
  16. A. Hongsingthong, I. A. Yunaz, S. Miyajima, M. Konagai, "Preparation of ZnO thin films using MOCVD technique with $D_2O/H_2O$ gas mixture for use as TCO in silicon-based thin film solar cells", Sol. Energy Mater. Sol. Cells, Vol. 95, No. 1, pp. 171-174, 2011. https://doi.org/10.1016/j.solmat.2010.04.025
  17. H. Zhang, B. Ding, T. Chen, "A high efficiency industrial polysilicon solar cell with a honeycomb-like surface fabricated by wet etching using a photoresist mask", Appl. Surf. Sci., Vol. 387, pp. 1265-1273, 2016. https://doi.org/10.1016/j.apsusc.2016.07.039
  18. S. B. Kim, S. M. Iftiquar, D. H. Lee, H. J. Lee, J. H. Kim, J. H. Jung, D. H. Oh, V. A. Dao, J. Yi, "Improvement in Front-Contact Resistance and Interface Passivation of Heterojunction Amorphous/Crystalline Silicon Solar Cell by Hydrogen-Diluted Stack Emitter", IEEE J. Photovolt., Vol. 6, No. 4, pp. 837-845, 2016. https://doi.org/10.1109/JPHOTOV.2016.2553779
  19. J. -Y. Li, C. -H. Hung, C. -Y. Chen, "Hybrid black silicon solar cells textured with the interplay of copper-induced galvanic displacement", Sci. Rep., Vol. 7, pp. 17177, 2017. https://doi.org/10.1038/s41598-017-17516-6
  20. L. Chen, Q. Wang, W. Chen, H. Huang, X. Shen, "Investigation of a novel frosted glass with regular pit array texture", J. Mat. Proc. Techno., Vol. 238, pp. 195-201, 2016. https://doi.org/10.1016/j.jmatprotec.2016.06.001
  21. T. Maier, D. Bach, P. Mullner, R. Hainberger, H. Bruckl, "Antireflective surface structures in glass by self-assembly of SiO2 nano particles and wet etching", Opt. Express, Vol. 21, No. 17, 20254, 2013. https://doi.org/10.1364/OE.21.020254
  22. H. S. Park, M. H. Shin, H. S. Kim, S. B. Kim, A. H. Tuan Le, J. Y. Kang, Y. J. Kim, D. P. Pham, J. H. Jung, J. Yi, "Investigation of 3-dimensional structural morphology for enhancing light trapping with control of surface haze", Opt. Mater., Vol. 66, pp. 404-409, 2017. https://doi.org/10.1016/j.optmat.2017.02.039
  23. S. Q. Hussain A. H. Tuan Le, K. Mallem, H. S. Park, M. K. Ju, Y. J. Kim, J. H. Cho, J. J. Park, Y. K. Kim, J. Yi, "Using the light scattering properties of multi-textured AZO films on inverted hemisphere textured glass surface morphologies to improve the efficiency of silicon thin film solar cells", Appl. Surf. Sci., Vol, 447, pp. 866-875, 2018. https://doi.org/10.1016/j.apsusc.2018.03.143
  24. H. S. Park, S.-H. Nam, M. H. Shin, M. K. Ju, Y.-J. Lee, J.-H. Yu, J. H. Jung, S. B. Kim, S. H. Ahn, J.-H. Boo, J. Yi, "Method for Fabricating Textured High-Haze ZnO:Al Transparent Conduction Oxide Films on Chemically Etched Glass Substrates", J. Nanosci. Nanotechnol. Vol. 16, No. 5, pp. 4886-4892, 2016. https://doi.org/10.1166/jnn.2016.12223
  25. H. S. Park, M. H. Shin, H. S. Kim, S. B. Kim, A. H. Tuan Le, Y. K. Kim, S. H. Ahn, J.-J. Jeong, J. Yi, "Wideband Light Scattering of Periodic Micro Textured Glass Substrates for Silicon Thin-Film Solar Cells", J. Nanosci. Nanotechnol., Vol. 17, No. 11, pp. 8562-8566, 2017. https://doi.org/10.1166/jnn.2017.15154
  26. H. S. Park, Y. -J. Lee, S. H. Ahn, S. B. Kim, J. Yi, "Effect of wet textured glass surface morphology on the haze ratio and aspect ratio for amorphous silicon thin film solar cells", J. Renew. Sustain, Energy, Vol. 6, No. 5, 053141, 2014. https://doi.org/10.1063/1.4899198
  27. S. M. Ji, K. J. Song, T. B. Nguyen, N. S. Kim, H. Lim, "Optimal Moth Eye Nanostructure Array on Transparent Glass Towards Broadband Antireflection", ACS Appl. Mater. Interfaces, Vol. 5, No. 21, pp. 10731-10737, 2013. https://doi.org/10.1021/am402881x