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

摘要

The results on growth and magnetotransport characterization of AlGaN/GaN heterostructures obtained by plasma assisted molecular beam epitaxy on dislocation-free (below 100 cm~(-2)) GaN high pressure synthesized bulk substrates are presented. The record mobilities of the two dimensional electron gas (2DEG) exceeding 100000 cm~2/Vs at liquid helium temperature and 2 500 cm~2/V s 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.