Flexible CdTe solar cells on polymer films

Lightweight and flexible CdTe/CdS solar cells on polyimide films have been developed in a 'superstrate configuration' where the light is absorbed in C dTe after passing through the polyimide substrate, The average optical tran smission of the approximately 10-mum-thin spin-coated polyimide substrate l ayer is more than similar to 75% for wavelengths above 550 nm. RF magnetron sputtering was used to grow transparent conducting ZnO:Al layers on polyim ide films, CdTe/CdS layers were grown by evaporation of compounds, and a Cd Cl2 annealing treatment was applied for the recrystallization and junction activation. Solar cells of 8.6% efficiency with V-oc = 763 mV, I-sc = 20.3 mA/cm(2) and FF = 55.7% were obtained. Copyright (C) 2001 John Wiley & Sons , Ltd.