An experimental study of the energy band alignments of B(Al, Ga)N heterojunctions

Abstract

The range of applications of the common III-nitride semiconductors (Al, Ga, In)N can be extended through bandgap engineering with the inclusion of boron and forming their heterojunctions. In this study, the band alignments of B(Al, Ga)N alloys with common III-nitrides are investigated using x-ray photoemission spectroscopy. A type-I straddling-gap band alignment is identified for a B0.06Ga0.94N/AlN heterojunction with a valence band offset (VBO) and conduction band offset (CBO) of 1.1 ± 0.2 and 1.8 ± 0.2 eV, respectively, whereas a type-II band alignment is observed on a B0.06Ga0.94N/GaN heterojunction with a VBO of 0.3 ± 0.2 and a CBO of 0.2 ± 0.2 eV. In addition, a type-I band alignment is deduced for both the B0.13Al0.87N/AlN and B0.13Al0.87N/GaN heterojunctions.