Cubic structured silver antimony sulfide-selenide solid solution thin films for sustainable photodetection and photovoltaic application

Abstract

Exploration of new materials for thin film photovoltaics has grown considerably to eliminate harmful and expensive material components in the large-scale production. In the present work, we report preparation of AgSbS2−xSex thin films by heating Ag2Se-Sb2S3 precursor layers. X-ray diffraction patterns showed that AgSbS2−xSex thin films with varying stoichiometry x (0.58–0.84) crystallized in face centered cubic structure and a compact surface morphology in scanning electron microscopy analysis. Optical bandgap of the thin films decreased from 1.6 to 1.4 eV as selenium content in the films increased. Photovoltaic structures were fabricated using AgSbS2−xSex films of different x values as absorbers and CdS as window layers. The best device based on AgSbS1.28Se0.72 of thickness ∼400 nm yielded a Voc = 525 mV, Jsc = 15 mA/cm2, FF = 0.53 and a conversion efficiency of 4.2%, the highest value ever reported for this material. In addition, CdS/AgSbS1.28Se0.72 heterojunction was also performed as a self-powered photodiode. Further, simulation results using SCAPS-1D predict that photovoltaic performance of CdS/AgSbS2−xSex can be improved by adjusting the Se concentration and the absorber layer thickness in a single p-n junction configuration.