Multifunctional Vertical Bulk-Heterojunction Transistors With Amorphous GaO_x for Neuromorphic Perception-to-Decision

Multifunctional neuromorphic hardware has emerged as a promising paradigm to transcend the physical separation of sensing, memory, and computing inherent in traditional von Neumann architectures. The central challenge lies in developing integrated devices with high functional density for in-situ fusion of sensing, memory, and computing. Here, we propose a multifunctional vertical bulk-heterojunction transistor (MVBT) based on amorphous GaO_x dielectric layer, integrating four functions within a single device: deep-ultraviolet (DUV) photodetection, threshold neuronal firing, broadband optoelectronic synaptic function, and reconfigurable logic gates. In the two-terminal (gate-source) mode, the ultraviolet-selective photoresponse and electrochemical reactions of amorphous gallium oxide (a-GaO_x) enable deep-ultraviolet photodetection and neuronal firing, respectively. In the three-terminal mode, the organic bulk-heterojunction active layer supports broadband optoelectronic synaptic function from ultraviolet to near-infrared wavelengths. Asymmetric interfacial carrier-injection barriers further enable bias-reconfigurable AND/OR logic functions. In addition, a pixelated MVBT array demonstrates dual-mode image sensing and visual preprocessing. Building upon these multifunctional capabilities, an MVBT-based convolutional spiking neural network (CSNN) hybrid simulation architecture achieves a fingerprint recognition accuracy of 97.4%. This work provides a new strategy for constructing high-functional-density neuromorphic hardware integrating sensing, memory, computing, and decision-making.