Systematic investigation of III V Nitride material based UV detector structure for high responsivity

Abstract

Photodetectors based on III-V Nitride group material like AlGaN or GaN have newlineattracted a lot of interest in the field of optoelectronics and UV detection newlineapplications as they exhibit major desirable properties; high absorption in UV newlinerange, ultra-high breakdown voltage, high temperature tolerance and good newlinephotosensitivity. For efficient detection of the optical signal in UV wavelength newlinerange, high performance UV detectors with high sensitivity and low dark current newlineare required. Conventionally AlGaN MSM detector type is the most commonly newlineused structure among other detector types intended for various UV detection newlineapplications. In case of MSM detector structure, there is absence of p-type doped newlineAlGaN material and ohmic contacts which require heavy doping. Its planar newlinestructure design opens up several possibilities to modify its performance newlineparameters. Since metal electrodes shading effect limits its responsivity as well as newlineefficiency. Hence there is a requirement to optimize AlGaN MSM structure for newlinehigh responsivity in UV range. In present research work the research possibilities newlinefor improving AlGaN MSM PD performance by varying structure dimensions newlinehave been investigated. Previous research studies have proved that varying device newlinedimensions is not complicated as compared to alter device processing techniques. newlineIt is known fact that high density of defects and dislocations are still present in newlinestate-of-the-art of AlGaN detectors. Hence it is highly desirable that photocurrent newlineor responsivity of MSM structure should be as high as possible with reasonable newlinelow dark current density. newline