Study On PIN Type Radiation Detector Of AlGaN-Based Of Variable Components

In this paper, an ultraviolet radiation detector designed adopts the PIN structure of AlGaN-based of various components. Lattice mismatch of GaN and AlN is very close, the variable component structure can work without bias, having low dark current. Through adjusting Al component from 0.1 to 0.7 in intrinsic doping area gradually, it can absorb a very wide wavelength spectrum scope from 244 nm to 348 nm, the highest quantum efficiency reaches to 80%.This paper analyzes the differences of the structure and working principle of variable components of AlGaN-based radiation detectors, lists related to material parameters detailedly during the design, gives a detailed description of the motion characteristics of carrier microcosmicly on the microcosmic point, and the physical parameter model is established. Strong polarization effects of AlGaNGa Nxx/1? in the heterojunction caused band bending between a depletion layer and window layer interface, forming a triangular barrier, affecting the performance characteristics of the radiation detector. It analyses parameters of electrical characteristics of AlGaN radiation detectors, such as quantum efficiency, responsibility, transient response, dark current and so on. Absorption layer thickness and depleted layer thickness are discovered to affect electrical properties mostly.With the help of Silvaco TCAD, the paper analyzes reasons of detecting band shift, mainly by the diffusion of the photogenerated carriers of N zone and P zone. Through in-depth analysis of quantum efficiency and response spectrum, it finds that the reverse bias affects radiation detection performance; The Smaller concentration of intrinsic I doping area is,the higher photocurrent is. Detector quantum efficiency is the highest as optimal values for the thickness is 910 nm. P layer thickess makes the greatest influences on the detector. The smaller the thickness, the quantum efficiency is higher, and the dark current is higher so that it needs to design rationally the optimal value. Reducing the thickness of N layer can also enhance lef side’s quantum efficiency of cut-off wavelength.