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This thesis broadly deals with two aspects. Firstly, it describes possible alternatives to chemical doping in dimensionally scaled semiconductor devices based on alternative emerging materials and investigates the so-called “electrostatic doping (ED)” approach as a possible solution. In this work, various reported ED approaches have been reviewed and new device concepts have been proposed and investigated via TCAD simulations along with electrical and optical measurements of experimentally realized devices. The conditions for ED, i.e inducing localized n-type or p-type regions in semiconductor using suitable metal work functions and gate biases, have been established. Among various possible ED based devices, the thesis particularly focuses on exploring the prospects of utilizing high-barrier Schottky contacts for devices such as LEDs, bipolar-transistors without adding any chemical doping. The thesis also explores the use of extreme work function contacts such as molybdenum oxide (MoOx) for realizing high-barrier diodes with bipolar conduction capabilities. Secondly, this thesis investigates the possibility of utilizing atomic layer deposition (ALD) grown polycrystalline (poly-)GaN thin-films for device applications as a potential solution to low-cost GaN-on-Si technology platform. In this direction, various electrical and optical properties of ALD poly-GaN thin-films have been studied and their potential applications are discussed. The thesis also examines the applicability of various ED ideas developed in this work for ultimately realizing the functional ED-based devices in poly-GaN thin films. |
