Effect of source temperature on CSS-deposited CdS films in Ar for CdS/CdTe solar cells: A combined experimental and simulative study

This study presents a comprehensive investigation into the synthesis and characterization of cadmium sulfide (CdS) window layers for CdS/CdTe thin-film solar cells fabricated using the closed-space sublimation (CSS) method. The work focuses on optimizing the source temperature during CSS deposition under an Ar atmosphere as a cost-effective alternative to the commonly used He atmosphere. By systematically varying the source temperature, the study elucidates the growth behavior of CdS layers in an Ar environment and its influence on the performance of CdS/CdTe solar cells. The as-deposited CdS films were characterized in terms of their optical, morphological, and electrical properties. An optimal source temperature of 660 °C was identified, at which a small-area (0.12 cm²) dot solar cell achieved a power conversion efficiency of 5.7%, an open-circuit voltage (Voc) of 630.5 mV, a short-circuit current density (Jsc) of 17.8 mA cm⁻², and a fill factor (FF) of 51%. Under these conditions, the external quantum efficiency (EQE) reached a maximum value of 70%. SCAPS-1D (Solar Cell Capacitance Simulator) simulations were performed to further validate the experimental results.