Xiao Wang

Graduation Semester and Year

2005

Language

English

Document Type

Thesis

Degree Name

Master of Science in Physics

Department

Physics

First Advisor

Qiming Zhang

Abstract

The excellent physical and electrical properties of Gallium Nitride (GaN) have made it a good candidate in light-emitting diodes and UV detecting semiconductor materials. However, GaN's p-type doping has long been a difficulty. Although beryllium (Be) substitutials arise as shallow acceptors in GaN, the concentration of Be substitutials, and hence the population of holes, is not high enough. In the present work, formation energies of Be point defects and complex defects are calculated and compared by first-principles density functional theory (DFT) method. We find self-compensation is easily formed when Be substitutials and Be interstitials co-exist in GaN, which is responsible for the low solubility of Be p-type doping. We have examined the idea using oxygen as a co-doping element to overcome the self-compensation. The formation of oxygen involved complex in GaN has been studied energetically. The charge states have also been considered. The results are compared with the formation of Be-only complexes.

Disciplines

Physical Sciences and Mathematics | Physics

Comments

Degree granted by The University of Texas at Arlington

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