Enhanced photovoltaic effects of microwave-assisted polyol-synthesized Cu2(Pd/Zn)SnS4 kesterite nanoparticles

Kesterite materials show excellent optical and semiconductive properties for use as p–type absorber layer in photovoltaic (PV) applications, but they have a high open circuit voltage deficit (Voc,def) due to high antisite defect and secondary phase formation, resulting in poor device performance. This work reports a PV cell composed of Cu2PdSnS4 (CPTS) nanoparticles as an absorber layer yielding highly improved Voc of 900 mV, which is two times that of fabricated pristine Cu2ZnSnS4 (CZTS) PV cell. Improved PV cell parameters such as fill–factor (FF) of 83.4% and power conversion efficiency (PCE) of 1.01% were obtained for CPTS devices which are 3–fold that of pristine CZTS devices. Optical studies revealed enhanced redshift absorption for CPTS nanoparticles. Electrochemical studies show improved current production, high electron mobility and low charge resistance for CPTS nanoparticles. This study shows that the improved photovoltaic properties can be attributed to enhancement in the bulk properties when Zn atoms are replaced by Pd atoms in kesterite nanomaterials as absorber layer material for PV applications.