Lattice-matched InAlN/GaN two-dimensional electron gas with high mobility and sheet carrier density by plasma-assisted molecular beam epitaxy

We report the growth and electron transport studies of two-dimensional electron gases confined at the lattice-matched In0.17Al0.83N/ GaN heterostructure on GaN templates by plasma-assisted molecular beam epitaxy. The two-dimensional sheet carrier density, 2.68 x 10(13) cm(-2), at room temperature is the manifestation of spontaneous polarization charge differences between the MAIN and the GaN layers. The heterostructure shows the Hall mobilities of 1080 and 3330 cm(2)/V s at 300 and 20K, respectively. The variable temperature Hall measurements in the range of 20-300 K reveal that the mobility and sheet carrier density have been nearly independent of temperature below about 150 K, a typical behavior of 2DEG structures. The achievement of high mobility can be attributed to the improvement of MAIN epitaxial growth conditions and reduced alloy disorder scattering of carriers. (c) 2007 Elsevier B.V. All rights reserved.