A comprehensive comparative study of CdTe thin films grown on ultra-thin glass substrates by close-spaced sublimation and RF magnetron sputtering

Abstract

This study elucidates a comprehensive comparative study on the structural, morphological and electrical characteristics of cadmium telluride (CdTe) thin films grown on ultra-thin glass (UTG) substrates via close-spaced sublimation (CSS) and RF magnetron sputtering. Deposited CdTe films were characterized utilizing the X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and Hall effect measurement system. CdTe thin films were in cubic and hexagonal-cubic orientations based on the deposition methods. Micro-strain and dislocation density for sputtered films were very high compared to CSS films. Crystallite sizes were in the range of 30–40 nm for CSS films and 7–25 nm for sputtering films. Grain size was estimated to be around 2 µm and thickness was approximately 1.5 µm for both CSS and sputtering system. Resistivity was almost same as 6.98 × 104 Ω-cm and 6.57 × 104 Ω-cm for CSS and sputtered films, respectively. The experimental results suggest that the CdTe films grown by CSS might be favorable as the optimum absorber layer for solar cell application.