▎ 摘　　要

A graphene-Si junction is an attractive system as it is both CMOS-compatible and representative of very interesting van der Waals (vdW) heterostructures. In this paper, the full spectral photoresponse of the graphene-Si heterojunction is investigated in the photovoltaic mode by using Fourier transform infrared photocurrent spectroscopy. Two photoresponse bands at 980 nm and 1550 nm are measured, which are attributed to the photocarrier generations in Si and in the graphene-Si vdW junction, respectively. Peak detectivities of the Si and the vdW junction photoresponses are measured to be 1.3 x 10(9) cm Hz(1/2) /W and 1.3 x 10(8) cm Hz(1/2)/W, respectively. The band diagram of the heterojunction suggests an indirect spatial transfer process from graphene to silicon. The results are indicative of great potential of the graphene-Si vdW junction for photodetection in the infrared region. Published by AIP Publishing.