Fabrication, characterization and photovoltaic performance of Cd1−xMnxS window layer based CdTe and CdSe thin film solar cells

In this work, we successfully fabricated two thin-film solar cells with configurations ITO/Cd 1−x Mn x S/CdTe/Al (C1) and ITO/Cd 1−x Mn x S/CdSe/Al (C2) using the chemical bath deposition technique and thermal evaporation techniques. The structural, morphological, optical, and electrical properties of the deposited layers were systematically analysed using X-ray diffraction, field emission scanning electron microscopy, ultraviolet–visible spectroscopy, and the four-probe method. The results confirmed that all the deposited films exhibited a polycrystalline nature, where cadmium manganese sulfide and cadmium telluride crystallized in a cubic structure, while cadmium selenide adopted a hexagonal phase. Field emission scanning electron microscopy micrographs revealed uniform, compact, and crack-free surfaces with good adhesion to the substrate. Optical analysis showed that cadmium manganese sulfide possessed a high direct band gap and high transmittance values, making it a promising window layer material, whereas cadmium telluride and cadmium selenide exhibited lower band gap energies suitable for absorber layers. Electrical performance evaluation of thin-film solar cells indicated that the open-circuit voltage and short-circuit current density of the C1 device were higher than those of C2. Furthermore, the fill factor and overall power conversion efficiency demonstrated that the C1 cell achieved an efficiency of approximately 7.19%, outperforming the C2 cell with around 5.21%. The novelty of this work lies in the comparative evaluation of cadmium manganese sulfide as a tunable window layer for both cadmium telluride and cadmium selenide-based thin-film solar cells, revealing its significant potential to enhance device efficiency through band gap engineering. These findings suggest that cadmium manganese sulfide is a promising candidate for next-generation thin-film photovoltaic applications and can contribute to the advancement of sustainable renewable energy technologies.