Superior carrier confinement in InAlN/InGaN/AlGaN double heterostructures grown by metal-organic chemical vapor deposition

InAlN/InGaN/AlGaN double heterostructures were grown and characterized. Temperature-dependent Hall measurements show that the two-dimensional electron gas has a steady density over the entire temperature range tested and a superior transport property compared with the traditional InAlN/GaN single heterostructure at elevated temperatures. The improved performance was attributed to the back barrier, which enhanced the carrier confinement and prevented electrons from spilling into the buffer. In addition, the room-temperature electron mobility of the double heterostructure was 1293 cm2/Vs, which is the highest reported for an InGaN-channel heterostructure.