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

Abstract

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 × 10¹⁰ 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.