Characterization of very-thin high-efficiency corrugated silicon solar cells

Advanced cells with a corrugated structure which have a potential of over 25% efficiency were successfully fabricated by introducing highly selective hydrazine etching and an improved photoprocess. The best performance obtained to date is 16.9% and 17.4% efficiency for 50 mu m and 100 mu m thick cells, respectively, with a thick SiO/sub 2/ passivation layer at the front and a back-surface field (BSF) structure at the rear of the cell. The density of interface traps (D/sub H/) of the SiO/sub 2/ passivation layer fabricated under modified oxidation conditions reveals very small values of the order of 1*10/sup 9/ to 1*10/sup 10/ cm/sup -2/-eV/sup -1/. The BSF structure applied to the rear of the cell is assumed to have an effective surface recombination velocity of the order of 1*10/sup 2/ cm/s.<
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