Two dimensional hole gas induced by the heterointerface of nonpolar plane AlN(1 [formula omitted] 0 0)/H-terminated (1 0 0) diamond

Abstract

Tailoring the electronic states of the AlN/diamond (AlN/C) interface is critical to develop the next generation semiconductor devices such as the deep-ultraviolet light-emitting diode, photodetector, and high-power high-frequency field-effect transistor. In this work, we investigate the electronic properties of the nonpolar plane AlN(1 1¯ 0 0)/H terminated (1 0 0) diamond heterointerface by using first-principles method with regard to different surface structures of diamond (1 0 0) plane, a semiconductor feature is predicted at the interface of nonpolar plane AlN(1 1¯ 0 0)/C(1 0 0), and a two dimensional hole gas (2DHG) is generated when diamond surface is terminated by hydrogen. The charge transfer at the interface strongly depends on the surface termination of diamond, on which hydrogen suppresses the charge exchange at the interface. The band alignments of AlN/C heterostructures show a typical electronic character of the type-II staggered band configuration. The hydrogen-termination of diamond markedly increases the band offsets with a maximum valence band offset of 2.7 eV and a conduction band offset of 2.0 eV for the AlN(1 1¯ 0 0)/C(1 0 0). The observation of the 2DHG at the nonpolar AlN(1 1¯ 0 0)/HC(1 0 0) interface and the larger band offsets open the avenue for the development of novel high-power, high-frequency diamond power devices.