Nanocrystalline hydrogenated silicon (nc-Si:H) substrate configuration n-i-p solar cells\nhave been fabricated on soda lime glass substrates with active absorber layers prepared by plasma\nenhanced chemical vapor deposition (PECVD) and radio frequency magnetron sputtering. The cells\nwith nanocrystalline PECVD absorbers and an untextured back reflector serve as a baseline for\ncomparison and have power conversion efficiency near 6%. By comparison, cells with sputtered\nabsorbers achieved efficiencies of about 1%. Simulations of external quantum efficiency (EQE) are\ncompared to experimental EQE to determine a carrier collection probability gradient with depth\nfor the device with the sputtered i-layer absorber. This incomplete collection of carriers generated\nin the absorber is most pronounced in material near the n/i interface and is attributed to breaking\nvacuum between deposition of layers for the sputtered absorbers, possible low electronic quality of\nthe nc-Si:H sputtered absorber, and damage at the n/i interface by over-deposition of the sputtered\ni-layer during device fabrication.
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