Superstrate-type CuInSe/sub 2/ solar cells with chemically deposited CdS window layers

Chemically deposited CdS was used for window layers of superstrate-type CIS solar cells. The CBD-CdS layers had no pinholes and had higher optical transmission at short wavelengths than evaporated CdS layers, which led to the increase in Jsc. Relatively high substrate temperature of 450/spl deg/C was used for CIS deposition, resulting in high Voc due to improved crystallinity of CIS films. However, the interdiffusion and alloy formation at CIS/CdS deteriorated cell performance. The best cell yielded an efficiency of 8.1% with Voc=440 mV, Jsc=34 mA/cm/sup 2/ and FF=0.54 using near-stoichiometric (Cu/In=0.91-0.98) CIS films.