Selenium Thin-Film Solar Cell

A new selenium thin-film solar cell of superior performance has been developed. The cell incorporates an SnO2/CdSe/Se/Au structure and is fabricated at 250°C or lower by vacuum evaporation only. The maximum efficiency is attained at 60°C, and its value is 4.6% for an AM 1 (Air Mass 1), 100 mW/cm2. This indicates the possibility of using the cell at higher temperature. VOC, ISC and FF are 0.65 V, 13.5 mA/cm2 and 52%, respectively. The efficiency at 400 lx under a fluorescent lamp is 11.6%. The cell characteristics improved with aging owing to stress release, and stabilized after 40 days at room temperature. Stresses within the selenium film and the internal series resistance are regarded as the major factors determining the cell quality. This paper discussed the mechanism of operation of the cell, an MIS structure including a Schottky barrier.