A model of trap-assisted tunneling in GaN/AlGaN/GaN heterostructure based on exchange times

The work presents a physical model of trap-assisted tunneling that can quantitatively determine the effect of traps upon the total current through a GaN/AlGaN/GaN heterostructure. The model is based on expressing the occupation probability of the trapping centers by electrons in terms of thermal and tunneling exchange times. The occupation probabilities calculated in this way are then used to work out the generation-recombination rates occurring in the continuity equations. This allowed us to simulate I-V curves of the structure with disabled and enabled trap-assisted tunneling and to verify the sensitivity of the model to the effective phonon energy. Although the model is proposed and tested for a particular structure, it is more general and can be applied to other structures as well.