High‐Performance Self‐Powered Broadband Schottky Junction Photodetector Based on Graphene‐Silicon van der Waals Heterostructure

Abstract

The development of information sensing technology depends on overcoming the difficulties of high‐performance broadband photodetection by developing novel devices that incorporate new materials and structural innovations. The combination of silicon with two‐dimensional materials has made a breakthrough in the discoveries of high‐speed, highly sensitive, low‐power broadband photodetectors. Graphene (Gra) is an attractive 2D material because of its unique optical, electrical, mechanical, and thermal properties. Over a wide spectral range, the coupling of Gra and Si can exhibit appealing photosensing behavior. Herein, a high‐performance, self‐powered broadband Schottky junction photodetector formed by the van der Waals stacking of Gra over the n‐Si substrate is demonstrated. The device exhibits a remarkable broadband spectral response from the visible (405 nm) range to the infrared region (1,550 nm). The remarkable values of responsivity, detectivity, and external quantum efficiency of 300 mA W−1, 3.37×1011 Jones, and 90% are achieved, respectively, at 532 nm illumination with a fast rise time of 320 μs. The high‐speed, broadband photoresponse and economical manufacturing of this device make it a potential candidate for the optoelectronics market.