Ultra‐Low‐Power Vertical Organic Synaptic Phototransistors for Neuromorphic Vision Preprocessing

Abstract

Abstract The development of energy‐efficient synaptic devices is crucial for advancing neuromorphic computing beyond von Neumann architectures. While organic synaptic transistors offer advantages like ultralow power operation and flexibility, achieving biological‐level energy efficiency remains challenging. Here, a breakthrough vertical organic transistor is presented using monolayer graphene electrodes and rubrene single crystals. The device achieves an exceptional ON/OFF ratio (17.2 A cm⁻ 2 ON‐state and 6.0 µA cm⁻ 2 OFF‐state) through the thinning rubrene crystal and optimized Schottky barrier control at the graphene/rubrene interface. Remarkably, the transistor demonstrates fundamental synaptic functionalities including excitatory postsynaptic currents and paired‐pulse facilitation with unprecedented energy efficiency of 58 aJ per spike−significantly surpassing biological synapses. Furthermore, the study successfully implements retina‐inspired image preprocessing, validating the device's neuromorphic computing potential. This work establishes a new paradigm for developing ultralow‐power organic synaptic devices, addressing critical challenges in energy consumption that have limited previous vertical organic transistor designs.