Detection Of Wavelength In The Range From Ultraviolet To Near Infrared Light Using Two Parallel PtSe₂/thin Si Schottky Junctions

High-performance wavelength detectors have important application in many fields,such as artificial intelligence assisted driving,image sensing and medical diagnosis,etc.However,the wavelength detection range of the current wavelength detection technology is relatively narrow(400-700 nm),and the wavelength resolution is relatively low,which is not conducive to practical applications.Therefore,it is very urgent to propose high-performance wavelength detector with good sensing resolution and broadband detection range.In this thesis,the as-proposed wavelength detector which is composed of two parallel PtSe₂/thin Si Schottky junction photodetectors is capable of distinguishing wavelength in the range from ultraviolet to near infrared(UV-NIR)light(265 to 1050 nm).In this study,the performance of the single PtSe₂/thin Si Schottky junction photodetector was first researched.The results showed that the switching ratio and response speed of the photodetector can reach 1.6×10³ and 71/16?s under 660 nm light illumination.The photodetector also can work as a self-driving photodetector.At the same time,the photodetector has a good air stability.Subsequently,two PtSe₂/thin Si Schottky junction photodetectors were placed in parallel to form a wavelength detector and its performance was analyzed.In the range of 265-1050 nm,the photocurrent ratio and incident wavelength follows a typical bijection function,which shows the device can realize the function of wavelength detection.The theoretical simulation results of Synopsys Sentaurus Technology Computer Aided Design(TCAD)confirmed that the realization of the wavelength detector function is not only related to the light absorption rate of the two photodetectors,but also related to the thickness of the silicon.What is more,extensive analysis was performed to reveal how and to what extent working temperature and incident light intensity and the thickness of PtSe₂ layer will influence the performance of wavelength detector.The expression between the wavelength,photocurrent ratio and light intensity of incident light was summarized,and the errors of the expression was also analyzed.Remarkably,the wavelength detector has an average absolute error of±4.05 nm and an average relative error less than±0.56%.The wavelength detector proposed in this thesis has a simple device structure and high-resolution characteristics,which has important application value in wavelength detection.