CUINS2 WITH LAMELLAR MORPHOLOGY .1. EFFICIENT PHOTOANODES IN ACIDIC POLYIODIDE MEDIUM

CuInS2 grown in a steep temperature gradient acquires a peculiar lamel lar morphology, similar to that of layered compound semiconductors. Th in electrodes (of thickness down to 30 to 40 mum) can be prepared by c leavage, reducing series resistance in the bulk of the semiconductor. The liquid junction of n-CuInS2 With acidic polyiodide medium (2M HI, 2.5M CaI2, 40 mM I2) was investigated. The best photoanodes attained q uantum yields of monochromatic light of about 0.7 and conversion effic iencies above 7% under simulated AM1 sunlight. Their performance does not decrease substantially under moderately concentrated sunlight (300 to 400 mW cm-2), due to the small ohmic losses. Cell output appears q uite stable during the first week of operation, but irregular electrod e corrosion is observed, which may be detrimental to long term operati on.