Electrical and Optical Properties of Cu<SUB>2</SUB>ZnSnS<SUB>4</SUB> Films with Different Chemical Composition

Alternative Spectral Photoresponse in a p-Cu2ZnSnS4/n-GaN Heterojunction Photodiode by Modulating Applied Voltage

“…The 350 nm responsivity at −4 V are approximately the same as the peak value at zero bias, which was ascribed to the high probability of electron−hole recombination between the narrow "interface" bandgap, though the reverse applied voltage can expel the generated holes. It should be noted that the peak appears around 500 nm and shows a weak response in the long wavelength portion of the spectrum, indicating a very low collection efficiency in this range, 32 which can be attributed to the light with longer wavelength was mainly absorbed in the bulk CZTS; the light-generated carriers were easily recombined in the bulk during the transport process. 33 Time-dependent response of the device was measured under zero bias with turning on and off as 370 nm light irradiated on the device.…”