Electrodeposition and Characterization of CdTe thin films for photovoltaic applications

Abstract

Cadmium Telluride (CdTe) is direct band gap semiconductor, ∼ 1.45 eV at room temperature. It is one of the promising absorber materials for heterojunction thin film solar cell application due to high absorption coefficient and less carrier diffusion length. We have electrodeposited CdTe thin film using conventional three-electrode geometry onto FTO coated glass substrate from non-aqueous electrolyte at potential −0.625 V. As-prepared samples of CdTe were characterized thoroughly to study structural, optical, morphological, compositional and transport properties. The films were polycrystalline in nature with mixed cubic and hexagonal crystal structure without metallic phases. Highly crystalline, large grain, compact CdTe thin films have been obtained without post-deposition heat treatment. The calculated electrical parameter can be further improved upon post-deposition thermal heat treatment and/or chemical surface treatment to produce high efficiency thin film solar cell devices. The reported growth procedure could be suitable for development of flexible thin film solar cells devices on to plastic substrates.