A Low‐Toxic Colloidal Quantum Dots Sensitized IGZO Phototransistor Array for Neuromorphic Vision Sensors

Abstract The rapid development of optoelectronic devices with biomimetic synaptic behavior holds significant potential for neuromorphic visual applications. However, considerable challenges remain including convenient device fabrication and low toxicity materials innovation. Here, a heterojunction phototransistor is constructed using low‐toxic CuZnInSSe (CIZS) colloidal quantum dots and amorphous InGaZnO (IGZO), which demonstrates high specific detectivity of 3.4 × 10 15 Jones in visible light spectrum. Moreover, it is found that the photoresponse speed can be controlled via a ligand exchange treatment, through that the response speed can be adjusted from 0.3 to 11 s. This enables the device to operate in two distinct modes: a typical fast sensing mode and a neuromorphic visual mode. In the neuromorphic visual mode, the device's synaptic behavior can be tuned by manipulating light pulse intensity, frequency, wavelength, and gate voltage. As a demonstration, a phototransistor array effectively implements image pre‐processing functions, including color recognition, visual memorizing, and forgetting.