Photodetector based on Van der Waals heterojunction and preparation method thereof

Abstract

The invention discloses a photodetector based on a Van der Waals heterojunction and a preparation method thereof. The photodetector comprises an optical fiber, a Van der Waals heterojunction structure, a pair of fiber side wall metal electrodes and a pair of fiber end face metal electrodes. The fiber side wall metal electrodes and the fiber end face metal electrodes are connected. The Van der Waals heterojunction structure is located on the end face of the optical fiber, and comprises a tungsten disulfide film, a molybdenum disulfide film and a graphene film from bottom to top. A pair of fiberend face metal electrodes is connected with the graphene film on both ends of the Van der Waals heterojunction structure. The photodetector prepared by the invention can detect weak light in the near-infrared band and strong light in the full band, has the advantages of good stability and anti-interference ability, and has a wide application prospect in the fields of optical communication and light sensing.

Description

technical field [0001] The invention relates to the field of optoelectronic technology, in particular to the field of photodetectors. More specifically, it relates to a new ultra-high responsivity, high-speed response, ultra-broadband photodetector and its preparation method. Background technique [0002] A photodetector is a device that converts light signals into electrical signals. When the photodetector is irradiated by light, it will cause a change in its electrical conductivity, which can be detected by electrical methods. Photodetectors are widely used in various fields of military and national economy, and ultra-high-sensitivity photodetectors have made outstanding contributions in modern optical communication, environmental detection, biomedical research and other research fields. Photodetectors can be divided into two types, one is photon-type detectors, the semiconductor material in the detector directly absorbs photons to produce a change in conductivity, which ...

AI Technical Summary

Problems solved by technology

However, on the one hand, due to the influence of electron mobility and defects, its responsivity is often difficult to achieve extremely high, and the response speed is relatively slow; on the other hand, due to the limitation of the band gap of the two-dimensional semiconductor material itself, its The detection wavelength range is often small, limited to the visible light band

[0004] Combining graphene with a graphene-like two-dimensional material to form a van der Waals heterojunction can enhance the carrier mobility of the graphene-like two-dimensional material, thereby greatly improving the photoresponsivity of the detector, but the response speed remains Slower, detection wavelength range is still small

A variety of different graphene-like two-dimensional materials are combined to form a van der Waals heterojunction. Because they have different work functions, a built-in electric field can be formed to accelerate the separation and recombination of electrons and holes, thereby improving Response speed and photoresponsivity; due to the electronic transition between layers of different two-dimensional materials, the energy required for incident photons can be reduced, thereby expanding the detection wavelength range, but the photoresponsivity is still relatively small

Images