Monte Carlo study of device characteristics of GaN-based avalanche photodiode devices

Abstract

In this article, Monte Carlo method is used to study the characteristics of gallium nitride (GaN). Impact ionization is treated as an additional scattering mechanism, which is described by the Keldysh formula with the parameters determined by fitting the simulated results to the numerical calculation results. Based on simplified model, results of velocity overshoot and impact ionization rate of both carriers are calculated and analyzed. In addition, we get the device characteristics associated with impact ionization, i.e., gain, noise, and bandwidth (both electron- and hole-injected cases), which is compared to the reported experimental data and conventional theories. Moreover, we contrast the simulated device characteristics of GaN and the performance of several conventional materials.