Reversible Half Wave Rectifier Based on 2D InSe/GeSe Heterostructure with Near‐Broken Band Alignment

2D van der Waals heterostructures (vdWHs) offer tremendous opportunities in designing multifunctional electronic devices. Due to the ultrathin nature of 2D materials, the gate‐induced change in charge density makes amplitude control possible, creating a new programmable unilateral rectifier. The study of 2D vdWHs‐based reversible unilateral rectifier is lacking, although it can give rise to a new degree of freedom for modulating the output state. Here, a InSe/GeSe vdWH‐FET is constructed as a gate‐controllable half wave rectifier. The device exhibits stepless adjustment from forward to backward rectifying performance, leading to multiple operation states of output level. Near‐broken band alignment in the InSe/GeSe vdWH‐FET is a crucial feature for high‐performance reversible rectifier, which is shown to have backward and forward rectification ratio of 1:38 and 963:1, respectively. Being further explored as a new bridge rectifier, the InSe/GeSe device has great potential in future gate‐controllable alternating current/direct current convertor. These results indicate that 2D vdWHs with near‐broken band alignment can offer a pathway to simplify the commutating circuit and regulating speed circuit.