Low-dimensional nano photodetector based on in-plane asymmetric local field control and preparation method thereof

Abstract

The invention discloses a low-dimensional nano photodetector based on in-plane asymmetric local field control and a preparation method thereof. The device structure sequentially includes a substrate,an oxide layer, a nano semiconductor, source and drain electrodes and a dielectric layer from bottom to top. The preparation steps of the device are as follows: transferring ultra-thin zinc oxide (ZnO) nanosheets grown by using a CVD method onto a silicon substrate with the oxide layer, preparing the source and drain electrodes by using electron beam exposure, thermal evaporation and other processes, and then preparing a hafnium dioxide (HfO2) dielectric layer by using electron beam exposure, atomic layer deposition and other processes, and finally preparing a low-dimensional nano photodetector. By introducing asymmetric HfO2, the partial adsorption of charged gas molecules on the nanosheets is formed to control the concentration of carriers on both sides of the zinc oxide nanosheets, andthus an in-plane asymmetric local field is formed, the response speed of the device can be finally increased, and the device can also show an ultra-high detection rate. The scheme of the invention hasthe advantages of simple preparation, fast response speed, low dark current, high detection rate and low power consumption.

Description

technical field [0001] The invention relates to a low-dimensional nano photodetector device, in particular to a low-dimensional nano photodetector controlled by an in-plane asymmetric local field and a preparation method thereof. Background technique [0002] Due to their unique optical, electrical, magnetic and mechanical properties, two-dimensional nanostructured materials have gradually become the focus of researchers around the world in many fields such as nanodevices and functional materials. Regarding the study of low-dimensional nanostructure materials, whether it is the controllable synthesis of materials, the preparation of devices, or the study of low-dimensional physics directly related to size, there are still many problems to be solved in each link. Among them, zinc oxide (ZnO) is a typical two-dimensional material, a typical wide bandgap (3.7eV) semiconductor material, which has relatively special photoelectric conversion properties, and is also called the thir...

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Problems solved by technology

[0003] However, ZnO-based photodetectors have a high intrinsic carrier concentration due to their abundant surface states and lattice defects, so there is a persistent photoconductivity phenomenon, which greatly reduces the response speed of the device, thus seriously affecting the photoelectric performance of the device. Detection performance

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