Date of Award
Doctor of Philosophy (PhD)
Electrical and Computer Engineering (Holcomb Dept. of)
Specialized and optimized low pressure direct oxidation technique have been implemented to synthesize high quality VO2 thin films on various substrates (sapphire, SiO2/Si, AT-cut quartz, GaN/AlGaN/GaN/Si and muscovite). Structural and surface characterization methods such as X-ray diffraction, Raman spectroscopy and atomic force microscopy have been administered on the grown VO2 films which indicate their material quality. Transition of characteristics of the VO2 films are caused by semiconductor metal transition (SMT). This phenomenon is attributed as the change maker in transition of resistivity and transmitted optical power through the VO2 films. Apart the substrates mentioned, metal doped VO2 films have been synthesized and characterized on quartz and muscovite, which are found to have transition temperature near the room temperature level, indicating to the possibility of high sensitive VO2 based sensors to be manufactured. Also, the VO2 films on flexible muscovite displays the direct effect of mechanical strain on the electrical and optical characteristics of the films. After metal finger patterning and releasing the VO2 membranes from the synthesized thin films, combination of all these characteristics of VO2 thin film is the reason of transmitted infrared beam through the VO2 membrane being modulated periodically due to implementation of external electric field at different frequencies.
Azad, Samee, "Investigation of VO2 thin films and devices for opto-electromechanical applications" (2023). All Dissertations. 3400.