Efficient high-deposition-rate all-hot-wire hydrogenated amorphous silicon n-i-p solar cells

• Published in: Conference Record of the Twenty-Eighth IEEE Photovoltaic Specialists Conference - 2000 (Cat. No.00CH37036) pp. 717 - 720
• Main Authors: Qi Wang, Iwaniczko, E., Yueqin Xu, Nelson, B.P., Mahan, A.H., Crandall, R.S., Branz, H.M.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2000
• Subjects: Amorphous silicon; Chemical vapor deposition; Hydrogen; Laboratories; Phase change materials; Photovoltaic cells; PIN photodiodes; Plasma temperature; Substrates; Tungsten
• ISBN: 0780357728; 9780780357723
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2000.915970

Efficient all-hot-wire chemical vapor deposition (HWCVD) hydrogenated amorphous silicon (a-Si:H) n-i-p solar cells have been demonstrated. Using HWCVD, we made the intrinsic layer deposited at 17-20 /spl Aring//s and the doped layers at 5-10 /spl Aring//s. An initial efficiency of 7.1% and a stable efficiency of 5.4% after 1000 hours of 1-sun light-soaking have been achieved on untextured stainless-steel (SS) substrate. This efficiency improvement results primarily from incorporating into the p/i interface about 60 /spl Aring/ of on-the-edge a-Si:H material grown just below the condition that would lead to the transition to microcrystallinity. We also optimize p-layers in solar cells by varying p-layer thickness, substrate temperature, trimethylboron gas flow rate, and chamber pressure. The cell's fill factor increases from 0.60 to 0.68, and the open-circuit voltage increases from 0.86 to 0.88 V. Recently, we improved the light-trapping by depositing the solar cell on textured Ag/ZnO-coated SS supplied by Uni-Solar, and we obtained an all-HWCVD record initial efficiency of 8.7%.