Impact of Evaporation Rates of Cd and Te on Structural, Morphological, Optical, and Electrical Properties of CdTe Thin Films Deposited by a Two-Sourced Evaporation Technique

Abstract

A two-sourced evaporation technique was used for deposition of cadmium telluride thin films onto scratch-free transparent glass substrates, using Cd and Te as two different evaporants. Nine samples were deposited at three Te evaporation rates, that is, 6.5, 4.5, and 2.5 nm/s as a function of three substrate temperatures at 400, 300, and 200 °C respectively, keeping the Cd evaporation rate fixed at 2.7 nm/s. All the samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), optically by Lambda 900 UV/vis/NIR spectrophotometer and electrically, that is, DC electrical resistivity, by the van der Pauw method at room temperature. Content composition was investigated by energy-dispersive X-ray analysis. Strong mutually supporting effects on structure, morphology, optical transmission, reflection, and electrical resistivity were observed.