Wafer-scale bias-reconfigurable optoelectronic micro-synapses with integrated functions of red emission and...

Despite the evident advantages of multifunctional integrated devices in compactness and integration density, achieving efficient coexistence of photodetection, synapse-like memory and red-light emission in one monolithic unit remains an extraordinary challenge due to profound conflicts in carrier recombination, separation, and storage. Here, we effectively mitigate these long-standing limitations by developing a wafer-scale gallium nitride (GaN)-based optoelectronic micro-synapse that integrates red light emission, self-powered photodetection, and bias-reconfigurable synaptic plasticity within a single micro-device. Red emission is realized through a simple quantum-dot color-conversion layer on a blue GaN micro-LED, avoiding the efficiency bottleneck of native red emitters while preserving device scalability and color stability. Beyond light emission, the same junction operates as a zero-bias self-powered photodetector. Under optical stimulation and global bias modulation, the device further demonstrates rich optoelectronic synaptic behaviors. The demonstrated platform provides a scalable and manufacturable route toward integrated neuromorphic vision systems.