Simulation of trap-assisted tunneling effect on characteristics of gallium nitride diodes

In this paper, simulations of I-V characteristics and band structures of magnesium and silicon doped gallium nitride diodes are presented. The numerical algorithm is based on the drift-diffusion semi-classic model, with the van Roosbroeck differential equation system involved. The model accounts for trap-assisted tunneling, which provides better agreement between the predicted and experimental I-V characteristics of p-n junctions in the low-bias range. We have performed one-dimensional simulations of devices. We compare the results with the results obtained from the standard drift-diffusion model. It is shown that taking the trap-assisted tunneling into account leads to good agreement with experimental data. We also demonstrate that a high doping of the p-n junctions may significantly increase the nonradiative recombination rate due to the prescribed effect. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730772]