Material Science and Engineering

Biography

Biography: Manorama Lakhe

Abstract

We have investigated the effect of low-temperature (80°C) heat treatment onto CuInTe2 (CIT) thin films prepared by one-step electrochemical synthesis technique. Aqueous precursor solution consisting ionic species of Cu, In and Te with pH 4.0 was used to optimize the deposition potential using cyclic voltammetry (CV). A conventional three-electrode geometry consisting working, reference and counter electrodes was used for the potentiostatic electro-deposition of CIT films onto CdS substrate. CdS layers were deposited onto fluorine doped tin oxide (FTO) conducting substrates by chemical bath deposition technique. The structural, optical, morphological, compositional, and transport properties were studied with the aid of XRD, Raman, HR-TEM, UV-Visible, FESEM, EDAX and I-V and C-V measurements. As-deposited samples were amorphous in nature, however upon heat treatment at 80°C for 30 minutes, the highly crystalline CIT thin films with tetragonal crystal structure were revealed. The values of energy band gap of the film deposited at -0.7 and -0.8 V versus Ag/AgCl was estimated to be in the range 1.02 to 1.08 eV. Compact, uniform, void free and well adherent films were deposited at -0.7 and -0.8 V. As the samples were heat treated at 80oC for 30 minutes therefore not much visible change in the surface morphology was observed after heat treatment. In-rich films were electrodeposited for above potentials, however after heat treatment sample deposited at -0.8 V showed the stoichiometric composition. Non-ohmic, schottky diodes are formed with Au metal contact in all cases. The dark current in I-V measurement was found to be increased by twoorders of magnitude after heat treatment. This low-temperature heat treatmentis advantageous for the fabrication of low temperature CIT based solar cell devices onto flexible substrates.