Defense Date

2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Nanoscience and Nanotechnology

First Advisor

Michael Reshchikov

Abstract

This study explores the potential of beryllium (Be) as an alternative dopant to magnesium (Mg) for achieving higher hole concentrations in gallium nitride (GaN). Despite Mg prominence as an acceptor in optoelectronic and high-power devices, its deep acceptor level at 0.22 eV above the valence band limits its effectiveness. By examining Be, this research aims to pave the way to overcoming these limitations and extend the findings to aluminum nitride and aluminum gallium nitride (AlGaN) alloy. Key contributions of this work include. i)Identification of three Be-related luminescence bands in GaN through photoluminescence spectroscopy, improving the understanding needed for further material development. ii)Determination of a Be-related acceptor level at 113 ± 5 meV above the valence band maximum (VBM) – significantly lower than that of Mg – suggesting greater potential for Be as a shallow acceptor. iii)Characterization of various red luminescence bands linked to donor complexes of nitrogen vacancies (VN) bound to substitutional acceptors Be, Mg, Ca in gallium (Ga) site. vi)Detailed analysis of the thermal and optical properties of Be-doped GaN, leading to a new model explaining the luminescence behavior observed in experimental data. Ultimately, this research provides insights into the use of Be in GaN doping, offering a path to potentially more efficient p-type doping strategies.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-9-2024

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