||Heterojunction with Intrinsic Thin layer (HIT) solar cells have some advantages about low temperature, low power, high open circuit voltage, and good temperature coefficient. They are better than Diffusion cells. In this study, ECRCVD was used for the deposition of high doping silicon thin films, and PECVD was used for the deposition of high doping silicon thin films and passivation layers. These thin films were deposited on single-crystalline silicon substrate to fabricate the silicon hetero-junction solar cells. The optical properties, electrical properties, and solar cell performance of hetero-junction solar cells were investigated. ECRCVD has advantage about high deposition, low working pressure, low ion bombardment, and no electrode contamination. The boron-doped layer was deposited by ECR as emitter in HIT solar cells. On the other hand, the high quality passivation layers and the back surface field of phosphorus-doped layer were deposited by PECVD to fabricate the silicon hetero-junction solar cells.|
We will investigate the optimization of carrier lifetime, different passivation layer, different wafer thickness, different doping layer, and different texture wafers. First, we are going to improve Voc and investigate the carrier lifetime with the structure of pi-ip and ni-in. The structure of HIT solar cell is Ag/ITO/a-Si:H(p)/a-Si:H(i)/c-Si(n)/a-Si:H(i)/a-Si:H(n)/ITO /Ag. The characteristics of hetero-junction solar cell on n-type planar substrate with the 10 nm-thick passivation layer are shown as follow: Voc = 690 mV in the area of 1 cm2. Moreover, the different thickness of wafers varying from 180 μm to 50 μm were also investigated. For 50 μm-thick substrate, the characteristics of hetero-junction solar cell on n-type planar substrate were shown as follow: surface recombination rate: 6 cm/s, Voc = 651 mV, Jsc = 29.28 mA/cm2, F.F. = 65.40 %, Efficiency = 12.46 %. This result is outstanding, therefore we will continue to research the HIT solar cells with ultra-thin substrates in the future. In our study, using the 20 nm-thick doping layer as emitter can achieve good conversion efficiency. In the end, we modulate the different textured wafers for HIT solar cells. The characteristics of 200 μm-thick hetero-junction solar cell with the grain size around 3~5 μm on n-type textured substrate are shown as follow: Voc = 660 mV, Jsc = 36.7 mA/cm2, F.F. = 71.1 %, Efficiency = 17.2 %.
KRI Report, No. 8: Solar Cells, February, (2005).
S Summers and H S Reehal, ”High rate growth of preferentially orientated crystalline silicon films by ECR plasma CVD”, 3rd World Conference on Photovoltaic Energy Conversion, p. 11–18, Osaka, Japan (2003).
Donald A. Neamen, Semiconductor Physics and Devices: Basic Principles (4e), McGraw-Hill, (2012).
Pelanchon, F., P. Mialhe, and J.P. Charles, “The photocurrent and the open-circuit voltage of a silicon solar-cell”, solar cells, 28(1): p. 41–55, (1990).
Schimpe, R.,Theory of reflection at the facet of a semiconductor-laser. Aeu-Archiv Fur Elektronik Und Ubertragungstechnik-International Journal of Electronics and Communications, 46(2): p. 80–85, (1992).
M. Quirk and J. Serda, Semiconductor Manufacturing Technology, Ch.11 Deposition, (2001).
莊達人編著, VLSI 製造技術, 高立圖書有限公司, p. 357, (1996).
A. Matsuda and K. Tanaka, Thin Solar Film, Vol. 171, (1982).
R. Robertson, D. Hils, H. Chatham, and A. Gallagher, “Radical species in argon‐silane discharges”, Appl. Phys. Lett, Vol. 544, (1983).
A. Matsuda, “Microcrystalline silicon. Growth and device application”, Journal of Non-Crystalline Solids, Vol. 338, p. 1–12, (2004).
Min Gu Kang a , and S. Tark, “Changes in efficiency of a solar cell according to various surface-etching shapes of silicon substrate”, Journal of Crystal Growth , Vol. 326, p. 14–18, (2011).
Netherlands Energy Research Foundation ECN, NL1755 ZG Petten, The Netherlands/ Simplified evaluation method for light-biased effective lifetime measurements.
T. S. Horanyi, T. Pavelka, and P. Tutto, “In situ bulk lifetime measurement on silicon with a chemically passivated surface”, Applied Surface Science, Vol. 63, p. 306–311, (1993).
Mikio Taguchi, Ayumu Yano, Satoshi Tohoda, and Kenta Matsuyama, “24.7% Record Efficiency HIT Solar Cell on Thin Silicon Wafer”, IEEE Journal of photovoltaics , Vol. 4, NO. 1, (2014).
Takahiro Mishima n, Mikio Taguchi, Hitoshi Sakata, and Eiji Maruyama, “Development status of high-efficiency HIT solar cells”, Solar Energy Materials & Solar Cells, (2010).
F.Jay n, D.Muñoz, T.Desrues, E.Pihan, and V.Amaralde Oliveira, ”Advanced process for n-type mono-like silicon a-Si:H/c-Si heterojunction solar cells with 21.5% efficiency”, (2014).
Thomas Muellera, Johnson Wonga and Armin G. Aberle, ”Heterojunction Silicon Wafer Solar Cells using Amorphous Silicon Suboxides for Interface Passivation”, (2012).
Christophe Ballif, Loris Barraud, and Antoine Descoeudres, ”A-Si:H/c-Si heterojunctions: a future mainstream technology for high efficiency crystalline silicon solar cells”, (2011).
R. Gogolin a,n, R.Ferre a, and M.Turcu, “Silicon heterojunction solar cells: Influence of H2-dilution on cell performance”, (2012).
Hseuh-Chuan Lee and Lu-Sheng Hong, ”High-rate deposition of a-Si:H thin layers for high-performance silicon heterojunction solar cells”, (2013).
Chia-Hsun Hsu, Shui-Yang Lien, and Dong-SingWuu, ”Effect of Hydrogen Content in Intrinsic a-Si:H on Performances of Heterojunction Solar Cells”, (2013).
許元錫, “The comparative study of electrical and conversion efficiency performance for homo-junction and hetero-junction c-Si solar cells”, 國立中央大學, (2014).
Donald A. Neamen, “Semiconductor Physics and Devices”, p. 177–180, (2003).
Satoshi Tohoda, Daisuke Fujishima, Ayumu Yano, Akiyoshi Ogane, Kenta Matsuyama, and Yuya Nakamura, “Future directions for higher-efﬁciency HIT solar cells using a Thin Silicon Wafer”, (2012).