Structural and Optical Properties of Sputtered Cadmium Telluride Thin Films Deposited on Flexible Substrates for Photovoltaic Applications

Abstract

Cadmium telluride (CdTe) is a photovoltaic technology based on the use of thin films of CdTe to absorb and convert sunlight into electricity. In this paper, polycrystalline CdTe thin films were deposited using radio frequency magnetron sputtering onto flexible substrates including polyimide and molybdenum foil. The structural and optical properties of the films grown at various sputtering pressures were investigated using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and UV/Nis/NIR spectrophotometry. The sputtering pressure was found to have significant effects on the structural properties, including crystallinity, preferential orientation, and microstructure. Deterioration of the optical properties of CdTe thin films were observed at high sputtering pressure.

Regulation of Substrate-Target Distance on the Microstructural, Optical and Electrical Properties of CdTe Films by Magnetron Sputtering

“…In previous studies, sputtering conditions, including substrate temperature [19], discharge current [15], substrate bias [20], and other factors [21,22,23] were systematically investigated by many researchers, indicating that the crystallinity of CdTe films can be optimized by adjusting the sputtering parameters; however, the function of substrate-target distance on propertied of CdTe films was few reported. Shin et al proved that substrate-target distance was a critical parameter affecting the growth of films, due to the kinetic energy of arrived atoms on the substrate [24].…”