Optical and Electrical Properties of Copper Doped Cadmium Oxy-Sulphide Quaternary Thin Films by MOCVD Technique

Abstract

Abstract:A prepared single solid source precursor was used for the deposition of copper doped oxy-sulphide thin films on glass substrate by MOCVD technique. This was achieved by the pyrolysis of the prepared precursors at 420°C with a flow rate of 2.5 dm 3 /min for 2 hours. The deposited films were characterized using Rutherford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), UV-visible spectrophotometry and four point probe method. RBS analysis showed that the expected elements are present while the thickness was estimated to be 889 nm. The SEM images of the deposited film showed a fine structure with densely packed grains of uniform grain size of about 80 nm, well distributed throughout the entire substrate which is polycrystalline in nature. The film revealed an average transmittance of 80% in the visible region with a direct bandgap of 2.41 eV. The absorbance of the film was observed to be low in the visible and near-infrared regions, and high in UV region. The values of 1. 17 × 10 Ω/□ and 10.40 Ω were obtained as the sheet resistance and resistivity of the film respectively. The deposited quaternary thin film is found to be a promising candidate as window layer and absorber layer for cost effective photovoltaics.