Exposure of Cu on microstructural and functional performance of Cadmium telluride solar cell

Abstract

Cadmium telluride (CdTe) thin-film solar cells are a top choice for cost-effective and efficient photovoltaic technology. Recent research has focused on enhancing the efficiency, stability, and scalability of these solar cells. This research study examines the impact of copper (Cu) exposure on the microstructural characteristics and functional performance of CdTe solar cells with doping thicknesses of 20 and 50 nm formed using the sol–gel method (“sol” a stable dispersion of nanoparticles, which is gradually transformed into a “gel” a network containing both liquid and solid components). The microstructure of Cu-doped CdTe nanocrystalline films is analyzed using scanning electron microscopy and X-ray diffraction to understand how Cu affects the CdTe films’ structure. The findings indicate that higher levels of Cu doping result in greater crystallite size and enhanced crystallinity while decreasing defects. When Cu is exposed to CdTe, the transmittance increases to 82%, and the optical band gap energy decreases to 1.755 eV. Additionally, functional performance metrics such as transmittance, absorption current, quantum efficiency, and I-V measurements are assessed. The highest absorption current achieved was 1.6 × 10⁻⁴ mA/cm² with a 50 nm absorber layer thickness. Increasing the thickness of Cu doping in the CdTe layer improved the performance of the CdTe absorber layer in the solar cell structure, resulting in an enhanced quantum efficiency of 88%.