Integrated Visual Sensing and Computing via Symmetry-Reconfigurable Photodiodes
This highlight summarizes a recent breakthrough in integrated visual sensing and computing using symmetry-reconfigurable photodiodes (SRPDs). The device architecture comprises a metal-semiconductor-metal configuration with AgBiS2 as the active layer, enabling dynamic symmetry breaking through voltage-controlled silver filament formation. The SRPD exhibits broadband photosensitivity from 360 nm to 1,550 nm at an illumination intensity of 115 mW cm-2, as demonstrated by multiwavelength time-resolved photocurrent responses. The device can be programmed into fifteen distinct photoresponsivity states, facilitating analog memory and neuromorphic computing. In imaging experiments, an SRPD-based sensory chip successfully captured images through visibly non-transparent inked glass at 808 nm, highlighting its capability for information-lossless acquisition in scattering media. Furthermore, the device achieved high-accuracy pattern recognition with nearly zero false neuron outputs when projecting specific patterns (├, ┬, ┤), each correlating to a unique current output. As a proof of concept, real-time eye-tracking control of an unmanned aerial vehicle (UAV) was demonstrated, enabling the UAV to follow and monitor a moving cyberdog. These results underscore the potential of SRPDs for processing-in-sensor applications, neuromorphic vision, and human-machine interfacing, offering a compact solution that merges sensing and computing functionalities.