Enhancement of Spectral Response in μ c - Si 1-x Ge x :H Thin-Film Solar Cells with a-Si:H/ μ c-Si:H P-Type Window Layers

• Published in: International journal of photoenergy 2015, Vol.2015 (2015), p.1-8
• Main Authors: Huang, Yen-Tang, Tsai, Chuang-Chuang, Hsu, Cheng-Hang
• Format: Article
• Language: English
• ISSN: 1110-662X; 1687-529X
• DOI: 10.1155/2015/841614

The hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon ( μ 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 SnO2:F-coated glass substrates. The substrates of SnO2:F, SnO2:F/ μ c-Si:H(p), and SnO2:F/a-Si:H(p) were exposed to H2 plasma to investigate the property change. Our results showed that capping a thin layer of a-Si:H(p) on SnO2:F can minimize the Sn reduction during the deposition process which had H2-containing plasma. Optical measurement has also revealed that a-Si:H(p) capped SnO2:F glass had a higher optical transmittance. When the 20 nm μ c-Si:H(p) layer was replaced by a 3 nm a-Si:H(p)/17 nm μ c-Si:H(p) double window layer in the cell, the conversion efficiency ( η ) and the short-circuit current density ( J SC ) were increased by 16.6% and 16.4%, respectively. Compared to the standard cell with the 20 nm μ c-Si:H(p) window layer, an improved conversion efficiency of 6.19% can be obtained for the cell having a-Si:H(p)/ μ c-Si:H(p) window layer, with V OC = 490 mV, J SC = 19.50 mA/cm2, and FF = 64.83%.