The effects of depletion layer on negative differential conductivity in AlGaN/GaN high electron mobility transistor

An analytical model for I–V characteristics of AlGaN/GaN based high electron mobility transistors (HEMTs) has been developed that is capable to predict accurately the effects of depletion layer thickness on negative deferential conductivity in positive gate biases. Salient features of the model are incorporated of fully and partially occupied sub-bands in the interface quantum well, combined with a self-consistent solution of the Schrödinger and Poisson equations and including the electron trap states effects. The calculated model results are in very good agreement with existing experimental data for Al0.2Ga0.8N/GaN HEMT device, especially in the liner regime.