Efficient and rapid Van der Waals heterojunction detector with unilateral depletion region and preparation method

Abstract

The invention discloses an efficient and rapid Van der Waals heterojunction detector with a unilateral depletion region and a preparation method. The detector structurally comprises a substrate, a Vander Waals heterojunction, a metal source electrode and a metal drain electrode which are sequentially distributed from bottom to top. According to the preparation method of the detector, a mechanically stripped black arsenic phosphide (AsP) sheet and molybdenum disulfide (MoS2) sheet are sequentially transferred to a silicon substrate through fixed-point transfer, so that the Van der Waals heterojunction is formed; and the metal source electrode and the metal drain electrode are prepared on the basis of electron beam lithography and a lift-off process, so that a heterojunction field effect transistor structure can be formed. The detector is characterized in that the heterojunction of the detector is a unilateral depletion pp junction which is different from a bilateral depletion pn junction. With the unilateral depletion heterojunction adopted, tunneling-assisted interface recombination and interface defect capture effects can be effectively inhibited, and therefore, high quantum efficiency, high photoelectric conversion efficiency and high response speed can be realized. The detector provided by the invention has the advantages of high signal-to-noise ratio, high quantum efficiency, photoelectric conversion efficiency and fast response, and can be applied to the field of solar cells.

Description

technical field [0001] The invention relates to a van der Waals heterojunction photodetection device, specifically referring to the use of p-type MoS 2 Form a van der Waals heterojunction with a unilateral depletion region with p-type AsP, reduce tunneling-assisted interface recombination and interface defect trapping effects, and achieve high quantum efficiency, photoelectric conversion efficiency, and fast response time. Background technique [0002] Two-dimensional van der Waals semiconductor materials have attracted widespread attention from scientists due to their special optical, electrical, magnetic and other physical and chemical properties and the peculiar properties of nanostructures. They are recognized as the basis for the development of next-generation nanoelectronic devices and optoelectronic devices. At the forefront of nanomaterials research today. Since there are no dangling bonds on the surface of two-dimensional van der Waals materials, and the layers are...

AI Technical Summary

Problems solved by technology

However, the currently reported two-dimensional van der Waals heterojunction detectors are all based on pn junctions in which both the p and n regions are carrier-depleted.

Both photogenerated electrons and holes need to pass through the heterointerface, resulting in very serious interfacial recombination, which greatly reduces the quantum efficiency of the device.

Secondly, there are many defect states at the interface of the two-dimensional van der Waals heterojunction prepared so far. These defect states will trap photogenerated carriers and slow down the response time of the device.

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