Growth and characterization of CuInS2 films grown by rf ion-plating

Films of the chalcopyrite semiconductor CuInS2 were grown by rf ion-plating at a relatively low substrate temperature of 400 degrees C, which allows us to use a large size inexpensive glass substrate, for various levels of substrate bias, ranging from +50 V to -50 V. The Cu and In compositions were controlled by varying the electron beam power of the Cu2S and In2S3 sources. There were significant differences in the surface morphology and crystallinity between films prepared under either negatively biased or floating conditions and films prepared under either positively biased or grounded conditions. Single phase CuInS2 films of good quality were obtained when the substrate was subjected to the floating conditions. Cu ions seem to play a very important role in the growth of CuxSy which acts as an accelerator for growing good crystalline CuInS2 at a relatively low temperature.