Ultrathin InAlN/GaN heterostructures with high electron mobility

The ultrathin InAlN/GaN heterostructure with 3 nm thickness was grown by metal organic chemical vapor deposition, and a room-temperature mobility of 2175 cm(2)/V.s at sheet density of 1.39 x 10(13) cm(-2) was achieved. Excellent crystalline and structural quality of the ultrathin InAlN/GaN heterostructure was revealed by transmission electron microscopy and atom force microscopy. The double periodicity of the Shubnikov-de Haas (SdH) oscillation was observed in the magnetoresistance measurements, and the energy separation between the two subbands was determined as 116 meV. It was found that the smaller interface electric field for the ultrathin InAlN/GaN was responsible for the smaller energy separations, which facilitated the occupation of the second subband. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim