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

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.