Large-Grained Cu_2ZnSnSe_4 Absorbers Prepared with Nano-Sized Cu-Zn-SnSe Cermet Pastes and Subsequent Selenization at 600-700°C

摘要

Large-grained Cu_2ZnSnSe_4 (CZTSe) absorbers for solar cells were fabricated by cermet paste-printing and subsequent selenization at relatively higher temperatures of 600-700°C under a two-selenide and step-heating procedure. CZTSe grains of 2-8 μm were obtained. Our non-vacuum approach chose the nano-sized powders to form cermet paste. This approach also involved Al_2O_3 substrate and a Cu(In,Ga)Se2 barrier layer. The major key to success is the selenization accompanied by two selenide pellets. Our CZTSe solar cell showed power conversion efficiency of 1.47%, an open-circuit voltage of 150 mV, a short circuit current density of 36.9 mA/cm~2, and a fill factor of 0.265.