Light-Stimulated Artificial Synapses Based on 2D Organic Field-Effect Transistors

2D organic semiconductors (OSCs) with atomically layered scaling structure have been attracting intensive attention in recent years. Benefiting from their unique size advantages, 2D materials have the potential to be immune to short-channel effects. High-performance photoresponsive transistors based on 2D OSC films with excellent light-stimulated synaptic properties are reported. They exhibit a high I-photo/I-dark (up to 1.7 x 10(5)), a competitive photoresponsivity (up to 3 x 10(3) A W-1), and an ultrahigh detectivity (exceeding 10(14) Jones). More interestingly, synapse-like behaviors including short-term plasticity and learning ability are successfully imitated. The 2D OSC films are prepared by a solution epitaxy method eliminating the effect of dielectric surface on the morphology of the deposited OSC films, which also simplifies the understanding of the photoresponse mechanism. It is believed that, by comparing the device performance with and without surface modification, synapse-like behaviors are derived from the interfacial charge trap effect. This is the first report of 2D OSC-based light-stimulated synaptic devices. This work not only expands the material selection range of current synaptic electronics, but may also provide an alternative simple and effective solution for the size-scaling of synaptic transistors in neuromorphic chips.