Cadmium Telluride (CdTe) Thin Film for Photovoltaic Applications

Cadmium telluride (CdTe) thin films are prepared by the dip-coating deposition technique under atmospheric pressure at different temperature. The optical band gap obtained within the range 1.63-1.60 eV. Crystallite sizes are obtained from XRD that are dependent on composition (Cd/Te) and baking temperatures. Raman spectra confirms the presence of transverse (TO) and longitudinal (LO) optical phonons in the CdTe structure. Films are good photoconductive in nature and could be used in photovoltaic applications. Index Terms—CdTe, optical band-gap, photoconductivity. I. I NTRODUCTION The interest on the different properties of photonic CdTe material is of considerable, due to its practical importance in technological applications such as, integrated optics, optoelectronics, solar energy conversion, gamma ray detection, and x-ray imaging. CdTe is of low cost thin film photovoltaic cells because of its direct band gap and have high absorption coefficient. CdTe could be doped with both n- and p- type materials using a large number of of preparation methods / techniques such as vacuum deposition (1), electro-deposition (2), (3), molecular beam epitaxial (4), metal-organic chemical vapour deposition (5), (6), close-space sublimation (7), (8) and screen printing (9), (10). It is necessary to have a detailed understanding of the basic properties of the materials for the fabricating the photovoltaic applications. In this present work we focuses on the basic and fundamental properties like optical, structural and photoconductive response of CdTe thin films grown by the dip-coating for the photovoltaic applications.