Studied On Application Of Terahertz Detector Of Topological Semimetal

As a crucial part of the terahertz field,the structure of the terahertz detector will affect the performance of the device.For example,the structure of the detector antenna affects the absorption of the device on the radiation or the improved structure affects the focusing ability or other methods.Therefore,the design of the detector structure is one of methods to improve the terahertz detector.At present,topological semimetal materials with unique properties are used in terahertz detectors,which can achieve the characteristics of high sensitivity and fast response.However,there are few researches on the improvement of topological semimetal terahertz detectors.In this paper,a series of studies on the topological semi-metallic material platinum telluride（Pt Te₂）are mainly carried out,and the terahertz detector device is prepared by mechanical stripping method and micro-nano processing process using the existing Pt Te₂ material,and then the performance of the detector device is tested and characterized by semiconductor parametric instrument and terahertz rapid response test system.Then,by changing the antenna structure and design structure of the device,the terahertz detector is improved,so that its performance indicators in all aspects are improved.The main research contents and results of this paper are as follows:1、In this paper,the topological semimetal Pt Te₂ material was prepared by mechanical stripping method and micro-nano processing technology.Subsequently,the semiconductor parameter instrument and the terahertz rapid response test system were used to characterize the performance of the detector.The enhanced terahertz field was achieved by changing the antenna structure of the device.The room temperature responsivity reached 3.85 A/W and the noise equivalent power reached 4.8 p W/Hz^1/2.This kind of detector has excellent response characteristics in terahertz band,so topological semi-metal has considerable development potential in the field of terahertz detector.2、We also propose a design integrated with the metalens to improve the terahertz detector,using electromagnetic simulation software CST to simulate the metalens,using a simple way to prepare the double-sided structure on a silicon wafer and using the terahertz near-field microscope to characterize the focusing effect of the metalens and test the terahertz detector.It is expected that the performance parameters of topological semimetal terahertz detectors can be improved by improving the device structure.