Simulation Of The Porous Silicon Carbide Schottky Diode-based Ultraviolet Detector

Silicon carbide(SiC)has demonstrated its excellent potential for high-frequency,high-power electronic devices and high temperature resistant optoelectronic devices due to its outstanding properties of wide bandgap,high break down electric field,low dielectric constant and high thermal stability.With the rapid development of detecting technology,high-performance ultraviolet(UV)photodetectors have been regarded as a research hotspot.SiC based Schottky UV detectors have great superiority of a low dark current,a fast response and easy to integration In recent years,they have been of great interest for a wide range of commercial and military applications such as missile tracking,flame detection,ozone monitoring and UV-astrophysics and so on.The refractive index and extinction coefficient parameters of SiC and porous SiC are calculated based on the absorption coefficient and the reflection coefficient of SiC in the near UV region together with the structural and reflective characteristics of the porous SiC.The problem of incomplete optical parameters in the whole ultraviolet band is solved.TCAD simulation software is used to simulate the SiC Schottky ultraviolet photodetectors.The spectral response,quantum efficiency,light responsivity,I-V characteristics,light/dark current and response time are investigated.The simulation results of the conventional SiC Schottky UV detector are as follows.The quantum efficiency and responsivity of the UV detector are 35.70% and 83.57 mA/W,respectively,at peak wavelength of 290 nm.Correspondingly,they are 36.14% and 84.53 mA/W in the experiment,which proves that our simulation results are basically consistent with the experimental values.The dark current and response time of the UV detector are 8×10-14 A and 21 ns,and their orders of magnitude are also same as the experimental results.The applied voltage,the thickness and concentration of the epitaxial layer play an important role in the UV detector responsivity.The simulation results of the Schottky UV detector based on porous silicon carbide are as follows.The quantum efficiency and responsivity of the UV detector at peak wavelength of 290 nm are 46.64% and 108.99 mA/W.Compared with the conventional photodetector,they are increased by 10.94% and 25.42 m A/W at the rate of 30.64%.The dark current and response time of the UV detector are 7.8×10-14 A and 35 ns,which are also the same order of magnitude as those of conventional photodetectors.The simulation results show that the quantum efficiency and responsivity of the porous silicon carbide based Schottky UV detector can be improved greatly while the dark current and response time increase modestly.