Developing Highly Crystalline, Single-Phase and Copper-Poor Cu2ZnSnSe4 Nanoparticles for Solar Cell Application

Abstract In this study, we report the synthesis of Cu(Zn,Sn)Se2 (CZTSe) nanoparticles by hot-injection method for application to the absorber layer in solar cells. The composition of elements in the CZTSe nanoparticles depends mainly on the injection speed of the Se precursor. By controlling the injection speed, we obtained complete single-phase CZTSe nanoparticles with high crystallinity and copper-poor composition. The nanoparticle diameter mainly ranged from ∼7 nm to 18 nm. The obtained CZTSe nanoparticles were used to fabricate a light absorber layer in the CZTSe solar cells. The cell exhibited performance, with short-circuit current density of ∼30.8 mA/cm2, open-circuit voltage of 0.39 V, fill factor of 0.47 and conversion efficiency of 5.8%.