Theoretical and Experimental Studies of III-Nitride Devices

In the field of semiconductor devices, the III-nitride material system, which is mainly made up of Indium Nitride (InN), Gallium Nitride (GaN) and Aluminum Nitride (AlN), has seen a great deal of attention over the past decade. Despite the maturity of this field of research, the growth mechanics and physics that govern the behavior of these devices is still poorly understood. For all the devices mentioned, there exist regions called heterojunctions, which can be defined as the interface between two materials of different band gaps. In the case of LEDs, these heterojunctions are typically at the interface of alloy regions, which are the Quantum Well (QWs) layer and the Electron-Blocking Layer (EBL). These regions have compositional fluctuations due to the random distribution of the atomic constituent in the alloy. This phenomenon, known as alloy disorder, has largely been insignificant in the studies of other III-V semiconductors. However, due to the higher effective mass and larger band gaps of the nitrides, disorder plays a significant role in understanding the carrier transport behavior within nitride devices. My research involves examining each of these layers and studying the hole transport behavior within these two types of heterostructures to better understand their electrical behavior. However, typical studies use LEDs as test structures, which are bipolar devices and are subject to recombination mechanisms. By using unipolar heterostructures, we can focus solely on the carrier transport within these structures without recombination complicating the analysis of the system, making them ideal test vehicles for theoretical models. My study involves simulating a three-dimensional unipolar p-type heterostructure that incorporates the fluctuations of the alloy composition within the alloy region. This would normally require solving for the wavefunctions of the system via Schrödinger’s equation. However, solving this equation in 3D is a computationally expensive tas