High mobility two-dimensional electron gas in AlGaN∕GaN heterostructures grown on bulk GaN by plasma assisted molecular beam epitaxy

Abstract

The results on growth and magnetotransport characterization of AlGaN∕GaN heterostructures obtained by plasma assisted molecular beam epitaxy on dislocation-free (below 100cm−2) GaN high pressure synthesized bulk substrates are presented. The record mobilities of the two dimensional electron gas (2DEG) exceeding 100000cm2∕Vs at liquid helium temperature and 2500cm2∕Vs at room temperature are reported. An analysis of the high field conductivity tensor components allowed us to discuss the main electron scattering mechanisms and to confirm unambiguously the 2DEG room temperature mobility values.