Study of electronic transport properties in AlGaN/AlN/GaN/AlGaN double-heterojunction transistor

The electronic transport properties in AlGaN/AlN/GaN/AlGaN double heterostructures are investigated by an analytical model, considering the effect of the modified Fang-Howard wave function. The alloy disorder scattering is assumed to be eliminated by the introduction of an AlN insertion layer, and the rest five possible scattering mechanisms, acoustic deformation potential scattering, piezoelectric field scattering, polar optical phonons scattering, interface roughness scattering, and dislocation scattering, are taken into consideration in the calculation. The relations of two-dimensional electron gas (2DEG) density and mobility with alloy composition in the top AlGaN barrier layer and AlGaN buffer layer and the channel thickness are estimated and discussed. Finally, we compare the temperature dependences of the 2DEG mobility in Al0.25Ga0.75N/AlN/GaN/Al0.05Ga0.95N double heterostructures and in the conventional Al0.25Ga0.75N/AlN/GaN single heterostructures and explain them with detailed scattering processes. Published under license by AIP Publishing.