Fabrication of Cu2ZnSnS4 screen printed layers for solar cells

Abstract Cu 2 ZnSnS 4 layers have been successfully fabricated on flexible polyimide substrates by screen printing. The microparticles of Cu 2 ZnSnS 4 , which is the main raw material for preparing screen printing paste, were prepared by wet ball milling and sintering methods. X-ray diffraction characterization results show the screen printed Cu 2 ZnSnS 4 layers were well indexed to single phase Cu 2 ZnSnS 4 . Scanning electronic microscopy images show the diameters and lengths of the as-prepared Cu 2 ZnSnS 4 microparticles are about 30–50 and 150–200 nm, respectively. The bandgap, sheet resistance, carrier concentration, and Hall mobility of the screen printed Cu 2 ZnSnS 4 layers were about 1.49 eV, 2.42×10 3 Ω, 3.81×10 18 cm −3 , and 12.61 cm 2 V −1 s −s at 25 °C, respectively. To evaluate the photoresponse of the screen printed Cu 2 ZnSnS 4 layers, complete photovoltaic cells with the structure of polyimide/Mo/Cu 2 ZnSnS 4 /CdS/ZnO:Al/Al-grid were further fabricated. The short-circuit current density, open-circuit voltage, fill factor, and efficiency of a typical photovoltaic cell with an active area of 0.15 cm 2 were 4.76 mA/cm 2 , 386 mV, 0.27, and 0.49%, respectively.