Mechanism of mobility increase of the two-dimensional electron gas in AlGaN∕GaN heterostructures under small dose gamma irradiation

Abstract

The effect of a small dose of gamma irradiation on transport characteristics of the two-dimensional electron gas (2DEG) in AlGaN∕GaN heterostructures was investigated. It is shown that the carrier concentration remains practically unchanged after an irradiation dose of 106rad, while the 2DEG mobility exhibits a considerable increase. The results are explained within a model that takes into account the relaxation of elastic strains and structural-impurity ordering occurring in the barrier layer under irradiation.