Enhanced Electron Mobility in AlGaN/InGaN/AlGaN Double-Heterostructures by Piezoelectric Effect

A striking effect of piezoelectric electron confinement on transport properites has been observed for the first time in nitride double-heterostructures. The two-dimensional electron gas mobility has shown to be drastically enhanced in the AlGaN/GaN/AlGaN double-heterostructure, compared with that in the conventional AlGaN/GaN single-heterostructure. The observed mobility enhancement results from the piezoelectrically enhanced electron confinement in the double-heterostructure. The electron transport properties in the AlGaN/InGaN/AlGaN double-heterostructure have also been examined for the first time. The increased capacity for the two-dimensional electron gas density has been observed in addition to the enhanced electron mobility. The AlGaN/(In)GaN/AlGaN double-heterostructures are promising for field effect transistor applications because of their superior electron transport properties.