Dual-functional vertical organic transistors for broadband photodetection and neuromorphic synaptic plasticity

Abstract Vertical organic field-effect transistors (vOFETs) offer a scalable platform for multifunctional optoelectronics, but the co-integration of broadband photodetection with biologically relevant synaptic plasticity has remained challenging. Here, we report a dual-functional vOFET incorporating a rubrene/F 16 -CuPc heterojunction and a monolayer graphene bottom electrode, which enables synergistic interfacial engineering for high-performance photodetection and neuromorphic processing. The device exhibits broad-spectrum responsivity (365–780 nm) of 24.1 A W −1 , an external quantum efficiency of 81.9%, and a detectivity of up to 3.75 × 10 11 Jones. Gate-tunable interfacial band alignment allows dynamic modulation of channel conductance. The transistor successfully emulates essential short- and long-term synaptic behaviors, including paired-pulse facilitation, frequency-dependent potentiation, pulse-number summation, and bidirectional long-term plasticity. Furthermore, retina-inspired image preprocessing capability is demonstrated using its intrinsic synaptic plasticity. Rubrene acts as a high-mobility medium for exciton generation and transport, F 16 -CuPc introduces interfacial dipoles that promote exciton dissociation and suppress recombination, and graphene serves as an ultrathin, transparent, and tunable contact that minimizes metal-induced interface states. This synergistic heterointerface design provides a robust pathway toward adaptive optoelectronic neuromorphic systems and bio-inspired visual processors.