A modelling study of carrier transport for III-V nitrides and superlattices, and development of TAMSEL

Abstract

Semiconductors play an integral role in today's society and have many applications. As one of the most talked about areas in semiconductor development - III-V
compound semiconductors have attracted special attention due to their superior
performance to silicon and high scalability. The study of III-V nitrides and their
heterojunction structures is one of the focuses. Studying and analyzing the electrical
and optical properties of III-V nitride semiconductors is a foundation. Accurately
characterizing these properties can guide material growth and wafer preparation, essential for designing devices based on these materials or structures. This thesis mainly conducted simulation and theoretical analysis around the carrier
transport of III-V nitrides. As a widely studied simulation of carrier transport, the
single-particle Monte Carlo method was applied in this study and is described in
detail in Chapter 2. We first simulated binary bulk nitrides: GaN, AlN, and InN. While
verifying the usability of the method, we focused on analyzing the impact of polar
longitudinal optical phonon and inter-valley scattering on electron transport
characteristics (Chapter 3). We then focused on ternary and quaternary alloys and
analyzed their electron transport properties. After completing the study of bulk
materials, our next stage is to target carrier transport (including electrons and holes) in
the GaN/AlGaN superlattice. First, we conducted an in-depth study of electron
transport in n-type GaN/AlGaN superlattice (Si-doped) (Chapter 5). We use Monte
Carlo simulations and single-band models, focusing on the low-field region to
understand transport behaviour. Secondly, we explore hole transport for p-type
GaN/AlGaN superlattice (Mg-doped). Considering the complexity of hole transport
compared to electron transport, we did not use a Monte Carlo model. Instead, we
study the effects of effective mass and scattering mechanisms, leading to potential
design optimizations (Chapter 6). Finally, this thesis also involves an additional
chapter (Chapter 7) about Tamm-Assisted Metasurface Emitting Lasers (TAMSELs),
which introduces the preliminary fabrication and measurement work.

Date of Award	7 May 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Judy Rorison (Supervisor)