Reconfigurable WSe ₂ Homojunction Phototransistor for Ultrasensitive Retinomorphic Dim-Light Vision and Multimodal Optoelectronic Logic Gates

Conventional CMOS image sensors face significant challenges in dim-light environments due to limited sensitivity and physical separation between sensing and processing units. While retinomorphic devices offer a promising alternative, most still suffer from insufficient photosensitivity, unidirectional photoresponse, and limited reconfigurability. Here, we present a reconfigurable WSe2 homojunction phototransistor capable of a gate-tunable bidirectional photoresponse for both ultrasensitive dim-light vision and multimodal in-sensor logic operations. The device demonstrates exceptional performance with an ultrahigh photocurrent on/off ratio of >107, a responsivity of 0.31 A/W, and a detectivity of 1.03 × 1012 Jones at zero bias, enabling self-powered imaging under ultralow illumination (1 pW). Furthermore, it successfully emulates retinal functions by achieving real-time edge enhancement and motion tracking under dim-light conditions through in-sensor convolutional processing and dynamically programmable photoresponse matrices. The device also implements reprogrammable optoelectronic logic gates (AND, NAND, XNOR, and NOT) and encrypted optical communication within a single device. This work provides a versatile platform for energy-efficient neuromorphic vision systems capable of complex processing under challenging light conditions with significant potential for applications in autonomous navigation, edge computing, and secure optical communications.