Morphological, Optical, and Electrical Studies of PVD CdTe Thin Films for Photovoltaic Applications

Abstract

Nano-crystalline CdTe films were coated on glass and silicon substrates using the vacuum evaporation (PVD) technique, with annealing temperatures of 25, 100, 150, and 200 °C. This study aims to create a simple photoelectric cell using the effective light-absorbing layer CdTe as a thin film and Si as an n-type semiconductor. Additionally, it investigates the properties of CdTe thin films annealed at various temperatures. The following equipment was used: XRD, UV-visible spectrophotometer, SEM, and AFM. Moreover, the electrical characteristics of the fully designed devices were tested using I-V measurements and the Hall effect. Thin-film photovoltaics could become the primary source of global electricity. The CdTe thin films were coated using thermal evaporation. The best efficiency was 0.99% for the CdTe/Si structure with Voc = 5.0 x 10-1 V, Jsc = 51.0 x 10-2 mA/cm2, FF = 0.39, at 25 °C, and the efficiency decreased with increasing temperature. It has been found that annealing temperatures have an impact on the size of crystallites, the values of energy gaps, and the electrical properties of CdTe thin films.