High conductivity CdS thin films formed by gas assisted chemical vapor transport (CVTG)

Formation of high conductivity CdS thin films by a new chemical vapor transport (CVT) method, employing a carrier gas, is reported for the first time. The film deposition was carried out in a quartz tube kept inside a tubular furnace. The chemical vapor 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 (Ω cm)^-1 and the films which showed intrinsic nature exhibited a conductivity of the order of 10^-8 (Ω cm)^-1. The new CVTG system is designed and further studies are in progress to obtain thin film solar cell structures employing this technique