Spectrum splitting approach based design simulation for multilayer chalcogenide solar cell architecture

Abstract

We report design simulation on multilayer solar cell architecture aimed at enhancing the absorption efficiency in antimony sulfide (Sb2S3) absorber based cell via spectrum splitting approach. The poor experimental efficiency chalcogenide absorber (say; ∼8% for Sb2S3) based solar cell has been attributed to inadequate rear contact barrier, a high concentration of point defects (both acceptor and donor) within the bulk, low carrier lifetime, and the presence of defects at the absorber/buffer interface. A hetero-structure design modification vis-à-vis experimental report using bandgap tunability of Sb2S3 via point-focusing spectral splitting technique approach has been implemented to upscale the efficiency. The incident solar spectrum has been split into three well defined regimes for a focussed bandgap matching to enable light absorption and minimize transmission and thermalization losses. The adopted point-focusing spectral splitting technique in this work has resulted in an efficiency of 18.0%, which is an advancement by 2.25 times over the highest reported efficiency of 8.0% in the literature for Sb2S3 absorber based solar cells.