Enhancement of Spectral Response in mu c - Si1-x Gex :H Thin-Film Solar Cells with a-Si:H/ mu c-Si:H P-Type Window Layers

• Published in: International journal of photoenergy 2015-01, Vol.2015
• Main Authors: Huang, Yen-Tang, Hsu, Cheng-Hang, Tsai, Chuang-Chuang
• Format: Article
• Language: English
• Subjects: Capping; Deposition; Glass; Photovoltaic cells; Silicon substrates; Solar cells; Thin films; Tin dioxide; Tin oxides
• ISSN: 1110-662X; 1687-529X
• DOI: 10.1155/2015/841614

The hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon ( mu c-Si:H) double p-type window layer has been developed and applied for improving microcrystalline silicon-germanium p-i-n single-junction thin-film solar cells deposited on textured SnO sub(2) :F-coated glass substrates. The substrates of SnO sub(2) :F, SnO sub(2) :F/ mu c-Si:H(p), and SnO sub(2) :F/a-Si:H(p) were exposed to H sub(2) plasma to investigate the property change. Our results showed that capping a thin layer of a-Si:H(p) on SnO sub(2) :F can minimize the Sn reduction during the deposition process which had H sub(2) -containing plasma. Optical measurement has also revealed that a-Si:H(p) capped SnO sub(2) :F glass had a higher optical transmittance. When the 20 nm mu c-Si:H(p) layer was replaced by a 3 nm a-Si:H(p)/17 nm mu c-Si:H(p) double window layer in the cell, the conversion efficiency ( eta ) and the short-circuit current density ( sub(JSC) ) were increased by 16.6% and 16.4%, respectively. Compared to the standard cell with the 20 nm mu c-Si:H(p) window layer, an improved conversion efficiency of 6.19% can be obtained for the cell having a-Si:H(p)/ mu c-Si:H(p) window layer, with sub(VOC) = 490 mV, sub(JSC) = 19.50 mA/cm super(2) , and FF = 64.83%.