材料科学および工学ジャーナル

Temperature Dependent Properties of Electrodeposited CuInTe2@ CdS Rod Like Heterostructures in Air and Argon Ambient

Abstract

Manorama G. Lakhe* and Nandu B. Chaure

CuInTe₂ (CIT) layers have been electrodeposited onto CdS coated FTO substrates at deposition potential -0.8 V verses Ag/AgCl reference electrode. The samples were annealed at four different temperatures viz, 350°C, 400°C, 450°C and 500°C for 20 minutes in air ambient, controlled argon ambient and Rapid Thermal Processesing (RTP) in presence of argon ambient for 5 shots. Samples were characterized by various characterization techniques to study structural, microstructural, morphological, compositional, chemical properties and concentration gradient of ionic species. Highly crystalline samples were obtained upon annealing the CIT layers in controlled argon ambient in tube furnace and RTP as a counter part of air annealed samples. Raman data shows removal of tensile strain upon annealing the samples in controlled argon ambient. Scanning Electron Microscopy (SEM) images shows increase in grain size for samples annealed at 350°C and 400°C in controlled argon atmosphere and in RTP. The high resolution Field Emission Scanning Electron Microscopy (FESEM) images shows further improvement in grain size in controlled argon atmosphere. Atomic Force Microscopy (AFM) images show rod like columnar morphology. XPS study shows the presence of Cu⁺, In³⁺, Te^2- and Te⁴⁺ states of copper, indium and tellurium. Time of Flight Secondary Ion Mass Spectroscopy (ToF SIMS) data shows almost uniform concentration of In and Te throughout the CIT layers annealed in controlled argon atmosphere. ToF SIMS data gives unique insight of concentration gradient of individual ionic species throughout the CIT layers and at CdS/CIT interface.