Organic/inorganic hybrid van der Waals heterostructure with an atomically abrupt interface has attracted great re-search interests within the field of multifunctional electronic and optoelectronic devices.The integration of organic rubrene films with inorganic Si semiconductors can avoid the atomic mutual-diffusion at the interface,and provide the possibility of forming two-dimensional van der Waals heterojunction accompanied with the type-Ⅱ energy band alignment,due to the transfer behaviors of majority carriers at the interface.In this study,the high-quality rubrene/Si van der Waals heterostruc-ture with an electronically abrupt junction was prepared,and a self-powered photodetector was then constructed based on this hybrid heterojunction.The photodetector demonstrated an excellent switching response to the 1064 nm monochro-matic light with large on/off current ratio of 7.0 × 103,the maximum photocurrent of 14.62 mA,the maximum responsivity of 2.07 A/W,the maximum detectivity of 2.9× 1011 Jones,and a fast response time of 13.0 μs.This study offers important guidance for preparing high-quality rubrene/Si hybrid van der Waals heterostructure with desirable band alignment,and the designed heterojunction photodetector has an important application prospect in the field of multifunctional optoelectronics.