Single-layer graphene, aluminum quantum dot heterojunction phototransistor device and preparation method thereof

Abstract

This invention discloses a monolayer graphene / aluminum quantum dot heterojunction photoelectric synaptic device and its fabrication method. The device sequentially comprises a silicon substrate, a silicon dioxide insulating layer, a monolayer graphene on the silicon dioxide insulating layer, a first test electrode and a second test electrode disposed on both sides of the monolayer graphene, an aluminum quantum dot layer covering the surface of the monolayer graphene and the electrodes, and a third electrode on the back side of the silicon substrate. The interface between the monolayer graphene and the aluminum quantum dots forms a graphene / aluminum quantum dot heterojunction, which can generate a stable built-in electric field under illumination, thereby effectively controlling the separation, trapping, and migration behavior of photogenerated carriers. The photoelectric synaptic device of this invention can realize various typical biological synaptic plasticity characteristics such as short-term memory, long-term memory, and double-pulse facilitation, and can controllably switch between synaptic promotion and inhibition plasticity by adjusting the gate voltage, illumination wavelength, and light intensity.

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