Built-in field effect on the electron mobility in AlN∕GaN∕AlN quantum wells

The authors demonstrated theoretically that compensation of the built-in electric field in AlN∕GaN∕AlN heterostructures with the externally applied perpendicular electric field may lead to the increase of the in-plane electron drift mobility. It has been shown that two- to fourfold increase of the room temperature mobility can be achieved for both nondegenerate and degenerate electron densities. Their calculations clarified the role of the intersubband electron transitions mediated by optical phonons in limiting the carrier mobility in GaN-based heterostructures. The tuning of the electron mobility with the perpendicular electric field may impact design of the high-power GaN∕AlGaN heterostructure field-effect transistors.