Integrating Intrinsic Charge Trapping Sites in Insolated MOF Nanoparticles based Dielectric Layer for Effective Photo/Synaptic Transistors

The design of charge trapping sites is the basic and critical factor to explore the organic photomultiplier phototransistor and synaptic transistors. There are few examples of charge trapping directly by constructing dielectric materials, because the traditional view is that the band gap of dielectric materials is very wide for difficulty of the trap and release of charge. This work employs the Liquid Phase Epitaxy (LPE) method to construct two-dimensional confined dielectric MOF-199 island-like film with 20 nm diameter as the dielectric layer of bulk heterojunction based photo/synaptic transistors. Diverse energy level structures of metal complexes nanostructures integrated intrinsic charge trapping sites with multi-channel electron and energy exchange to active layer. The multi-channel exchange combines the response advantages of machines and the human brain, while the intrinsic charge trapping avoids interface charge quenching. It demonstrates simultaneous high photocurrent and well long-term plasticity, a high phototransistor performance of photo-responsivity R=650.1A·W-1/specific detectivity Dshot*= 6.76e15 Jones, and efficient photonic synaptic transistors with maximum paired pulse facilitation (PPF) index of 142%, single-pulse remaining ratio 65%. All these results point out the organic phototransistors for emulate the functions of biological synapses, which indicate its potential as the building block of bionic electronic circuits systems.