Novel processes for large area gallium nitride single crystal and nanowire growth.

Abstract

Li, Hongwei 1975-, "Novel processes for large area gallium nitride single crystal and nanowire growth." (2005 I was born in a small, typical rural village in China. I couldn't remember but I could imagine the hardness my parents experienced at that time when people were still struggling for adequate food and clothing. I survived from twice serious drown when I was 2-3 years old, but resulted in serious cough from the accidents. My parents worried about me, spent every penny they had to try every recipe they could get to cure the disease. Thanks to my parents' carefully and meticulously effort, I finally recovered and grow strong enough to be here to achieve the dream.My father could have had gone to college after high school if there were no the culture revolutionary. My mother only had finished primary school and had to quit to support her family. Though not well educated, they know the importance of education for their children's future. With only about 1 acre land and almost everything being done by hands, they planted, irrigated, harvested the crops to feed the family, though most time the harvest has to be under the mercy of weather. They worked as long as 16 hours a day, sometimes even in the sweltering summer to try their best to give us a better living.Because of very less profits from only growing wheat, my father also grew vegetables to vi sell them on the market and did many kinds of small businesses to subsidize the family. I tried to help them by doing things as much as I could since I was in primary school. I still remember those times of hard labor works: I often got up early morning to help crop the vegetables for sale; I was waked up from sweet dream at midnight to pick up the sweet potato being dried on the land before the unexpected rain came; I helped plant the wheat with chilly water in the mid fall morning before sun rising; We cracked the peanuts by hands during the winter nights till the hands ached. I understand the arduousness my parents had gone through by experiencing these hard labor works. All these experiences provide me with valuable assets of hard working, frugality and always stimulate me to move forward.My parents are always proud of me and never stop supporting my pursuit. devices require the defect densities to be lower than 10 4 /cm 2 . So, the need for new processes to produce large size GaN crystals with defect densities less than 10 7 /cm 2 is immediate. In addition to large area single crystals (or wafers), the nanowires also present as an alternating platform for making devices. So, the processes for controlled synthesis, modifying and integrating sub 100 nm nanowires into electronic devices are of great interest.This thesis presents a new concept of 'self-oriented growth' of GaN platelets shaped crystals on molten gallium to produce near single crystal quality GaN films over large areas (>1 cm 2 ). The process involves direct nitridation of Ga films using nitrogen plasma at low pressures (few mTorr This thesis also presents direct synthesis approach for GaN nanowires ...

Plasma-assisted liquid phase epitaxy of gallium nitride using molten gallium.

“…The author suggested that the incorporation of nitrogen into the Ga melt induced the spreading behavior of the metal onto the quartz substarte. 147 In a similar manner, additions of others metals like, bismuth (Bi), tin (Sn), and indium (In) to Ga have been shown to reduce the surface tension of the alloy compared to that of pure Ga. 148 Moreover, Kleinbaum et al, who obtained GaN films via plasma-assisted LPE, stated that the ability of Ga to wet a surface is increased by adding hydrogen to the nitrogen plasma.…”

“…This conclusion is in good agreement with previous studies. 140,[146][147] An example of a Ga droplet exposed to nitrogen is presented in…”