A high-performance self-powered photodetector based on SnP₂S₆ in the visible light region

As promising candidates in optoelectronics, transition metal thiophosphates (MTPs) have attracted intensive research interest due to their strong light absorption and tunable bandgaps. As a member of the MTP family, SnP2S6 has demonstrated significant potential for application in photodetectors (PDs). Here, we report a SnP2S6 -based metal-semiconductor-metal (MSM) photodetector with asymmetric electrode contacts. The device demonstrated a responsivity of 146.82 mA W-1 and a detectivity of 8.0 x 10(10 )Jones in the visible light region. Moreover, it showed self-powered behavior at zero bias voltage with an ultra-low dark current, fast response speed, high responsivity and high detectivity. The self-powered response current of the device could be attributed to the net current generated by the unbalanced energy barriers of the two asymmetric Schottky contacts between the crystal and the gold electrodes. This work provides a possible way for the application of SnP2S6 -based PDs in portable energy saving devices.