PtSe₂/InP Mixed‐Dimensional Schottky Junction for High‐Performance Self‐Powered Near‐Infrared Photodetection

Abstract

Self‐powered near‐infrared (NIR) photodetectors utilizing low‐dimensional materials are promising owing to their low‐power‐consumption and superior photoresponse performance. The strong light‐matter interaction and other intriguing physical mechanisms (such as high mobility, dangling‐bond‐free surface) in 2D semiconductor materials, combined with the flexible fabrication of device structures, create new opportunities for the optoelectronic devices. Here, a self‐powered NIR Schottky junction photodetector is demonstrated by vertically stacking 2D PtSe2 film atop an InP wafer. The strong built‐in electric field formed at PtSe2/InP interface endows the device with self‐powered operation with an ultralow dark current of 45 pA at room temperature under 0 V bias. The responsivity and detectivity at 940 nm illumination reach up to 0.718 A W−1 and 4.37 × 1012 Jones, respectively. Furthermore, TCAD simulations showed that the significant electric field at the PtSe2/InP interface is pivotal for its superior self‐powered detection performance. Remarkably, the device achieves a high Ilight/Idark ratio exceeding 105 and a fast response time of 4.35/5.66 µs, and sensitivity to NIR light polarization. This study provides a new perspective for the integration of hybrid 2D materials with 3D semiconductors in the next‐generation optoelectronic devices and integrated systems.