A light-switchable polarity retina-inspired phototransistor for adaptive photo-sensing

The limited dynamic range and fixed response polarity of conventional photodetectors pose significant challenges for machine vision in real-world, rapidly changing illumination, leading to either blindness in low light or saturation in glare. We present a retina-inspired phototransistor based on a CdS–MoS2 van der Waals heterojunction that exhibits light-intensity-switchable photo-response polarity, enabled by gate-tunable charge recombination/injection dynamics. The device seamlessly integrates optical encryption and adaptive noise filtering in a single platform, achieving a 94.2% digit recognition accuracy under high glare. This work demonstrates a single-device platform that synergistically integrates adaptive perception, secure communication, and neuromorphic preprocessing, offering a compact and energy-efficient hardware solution for next-generation intelligent vision systems in robotics, surveillance, and human–machine interfaces.