Programmable Te/MoTe 2 van der Waals Heterojunction for Image Preprocessing and Dynamic Recognition

ABSTRACT Van der Waals materials and their heterostructures offer strong gate tunability, enabling multilevel and polarity‐switchable photoresponse states in programmable photodetectors for in‐sensor encoding and computing. However, current gate‐programmable photodetectors often rely on trap‐mediated mechanisms, where charge capture and release can lead to nonlinear weight modulation and slow transient response. Achieving linear modulation of photoresponse weights while maintaining fast photoresponse therefore remains challenging. Here, we present a Te/MoTe 2 reconfigurable photodetector governed by gate‐modulated interfacial built‐in fields. Under zero drain bias, the short‐circuit photocurrent can be continuously tuned from negative to positive values, giving rise to linear bipolar responsivity modulation with a coefficient of determination (R 2 ) of 0.99 over the V gs range from −44 to −14 V, which contains 31 experimentally distinguishable bipolar photoresponse states. A fast transient response of 3 µs is maintained during gate‐programmed polarity switching. The 3 × 3 device array further demonstrates pixel‐to‐pixel reproducibility in responsivity modulation and response speed, supporting convolutional‐kernel‐based image processing and event‐driven motion recognition. This work provides a built‐in‐field‐dominated gate‐programming strategy for low‐power, fast, and linearly reconfigurable optoelectronic devices for in‐sensor computing.