High efficiency large area a‐SiGe:H based multi‐junction solar cells using MVHF

Abstract

AbstractWe have developed high efficiency large area a‐Si:H and a‐SiGe:H multi‐junction solar cells using a Modified Very High Frequency (MVHF) glow discharge process. We investigated a‐SiGe:H deposition rate dependence of cell performance, and optimized MVHF a‐SiGe:H process at a deposition rate 2‐4 times that of a typical RF deposition. We conducted a comparative study for different cell structures, and compared the initial and stable performance and light‐induced degradation of solar cells made using MVHF and RF techniques. In additon to high initial efficiency, the MVHF cells also exhibit superior light stability, showing <10% degradation after 1000 hour of one‐sun light soaking at 50 °C. We also studied light‐induced defect level and hydrogen evolution characteristics of MVHF deposited a‐SiGe:H films and compared them with the RF deposited films (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)