First-principles calculations of point defects and impurities in nitride semiconductors*

III-nitride semiconductors (GaN, AlN, InN) and their alloys have enabled tremendous progress in a range of applications from wide-bandgap (WBG) power electronics to light-emitting devices.  Native point defects and impurities play an important role in hindering or aiding in the success of these applications.  Better control of point defects is still needed in order to improve materials quality and enable improved efficiency of devices.

I will show how first-principles calculations using hybrid functionals can be used to shed light on multiple aspects of this problem.  This includes the structural, electronic and optical properties of point defects, doping, energetics and electronic structure of alloys, radiative, non radiative and thermal emission processes due to defects.  Finally, I will show how the insights from this work can be used to engineer the material performance of emerging nitride semiconductors such as cubic and hexagonal boron nitride, boron containing III-nitride alloys (eg. BGaN and BAlN), and the II-IV-nitrides.

This work has been performed in collaboration with J. L. Lyons, J-X.Shen, C.E. Dreyer, A.Alkauskas, M. Turiansky, N. Adamski, and C.G. Van de Walle.