THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING   GEORGIA INSTITUTE OF TECHNOLOGY   Under the provisions of the regulations for the degree DOCTOR OF PHILOSOPHY on Friday, June 8, 2018 1:00 PM in IPST 114   will be held the   DISSERTATION PROPOSAL DEFENSE for   Haiyang Zou   "Application of piezotronic and piezo-phototronics"   Committee Members:   Dr. Zhong Lin Wang, Advisor, MSE Dr. Naresh Thadhani, MSE Dr. Zhiqun Lin, MSE Dr. Meilin Liu, MSE Dr. Bernard Kippelen, ECE   Abstract:     Third-generation semiconductor materials have superior performance with high voltage resistance, high frequency, high efficiency, high-temperature resistance and high radiation resistance, that they look to be the “core” of a new generation of information technology, energy saving, and smart manufacturing. They can have broad application prospects in many fields, and have attracted the attention of governments, industries and research communities all over the world and achieved rapid development. The typical materials such as GaN and ZnO simultaneously exhibit piezoelectric, semiconducting and photoexcitation properties. The piezoelectric polarization charges can be utilized to control/tune the charge carrier transport characteristics in these materials (piezotronic effect), and also used to tune the generation, transport, separation and/or recombination of charge carriers (piezo-phototronic effect). The coupling of these properties in these materials has resulted in both novel fundamental phenomenon and unprecedented device application, leading to the increasing research interests in the emerging field of piezotronics and piezo-phototronics. Functional electronic and optoelectronic devices are presented to illustrate the practical applications of the piezotronic and piezo-phototronic effects. Fundamental physics about the piezotronics and piezo-phototronics are further studied in this work. This will help to develop a full understanding of piezotronics and piezo-phototronics, and it also enables the development of the better performance of optoelectronics. By applying the two effects in a wide range of electronics/optoelectronics, we have shown they are effective approaches to modify the physical properties in piezoelectric semiconductors and a useful tool to study the physical model in a complex system.