Room-temperature topology insulator terahertz detector and preparation method thereof

Abstract

The present invention discloses a room-temperature topology insulator terahertz detector and a preparation method thereof. The detector comprises in order from bottom to top: a substrate, an oxide layer, a bismuth selenide thin film, a log antenna and metal source and drain electrodes. The preparation steps of the device comprise the steps of: transferring the bismuth selenide thin film, being subjected to mechanical exfoliation, with a rich surface state onto the substrate, utilizing a method of ultra-violet lithography or electron-beam lithography and combining a traditional exfoliation process to prepare the log antenna and the metal electrodes taken as a source electrode and a drain electrode, and forming a bismuth selenide thin film field-effect transistor structure. The surface-stateelectrons of the bismuth selenide thin film and crystal lattices generate asymmetry scattering under the irradiation of Terahertz light so as to achieve detection of rapid terahertz in a room temperature. The terahertz detector has advantages of high speed, wideband, high response and high integration level, belongs to a photovoltaic detector and lay the foundation of large-scale application of the room temperature terahertz detector.

Description

technical field [0001] The invention relates to a topological insulator photodetection device, in particular to a room temperature topological insulator terahertz detector and a preparation method thereof. Background technique [0002] Terahertz wave (Terahertz, THz) radiation refers to electromagnetic waves with a frequency between 0.1 and 10 THz (wavelength 30 microns to 3 mm). Coincidence, belonging to the far infrared band. Because it is located in the wave band where far-infrared and microwave intersect each other, there has been a lack of corresponding methods to generate and detect it for a long time, thus forming a THz gap (terahertz gap). [0003] The characteristics and applications of terahertz photons: (a) The quantum energy and black body temperature are very low; because the photon energy of terahertz waves is very low, it is not easy to ionize when it penetrates substances, so it can be used for safe non-destructive testing. [0004] (b) The vibration and ro...

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Problems solved by technology

However, the traditional method relying on the transition between quantum well subbands is difficult to achieve the purpose of radiation detection, because the photon energy of terahertz is less than the energy of thermal disturbance, and it is easy to reach saturation.

At present, commercial terahertz wave detectors that are widely used include thermal radiometers, but they need to work under low temperature conditions. The operating frequency of Schottky diodes is less than 1 terahertz, and the response speed of pyroelectric detectors is very slow. Therefore, it is necessary to explore new semiconductor materials and new functional devices to realize terahertz detection

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