Low-resistivity CdS thin films formed by a new chemical vapour transport method

Abstract

Formation of low-resistivity CdS thin films by a new chemical vapour transport (CVT) method, employing a carrier gas, is reported for the first time. Film deposition was carried out in a quartz tube kept inside a tubular furnace. Chemical vapour transport was done using a screen-printed film of CdS with CdCl2 as the flux incorporated in the film. The nature of the film depends on parameters like condensation temperature, cooling rate, substrate position etc. The extrinsic films showed an electrical conductivity of the order of 101 ( Omega cm)-1 and the films which showed intrinsic nature exhibited a conductivity of the order of 10-8 ( Omega cm)-1. A new CVT by gas system has been designed, and further studies are in progress to obtain thin film solar cell structures employing this technique.