Microwave Growth and Characterization of Zinc Oxide Single Crystal Microtubes for Optoelectronic Applications

本项目旨在了解单晶氧化锌微管的生长机理(S)及其与器件应用相关的物理和特性。通常，氧化锌单晶的制备有三种形式：大块晶体、薄膜和纳米线/纳米棒。最近，主要研究人员利用一种新颖的自封装微波生长(SEMG)方法制备了氧化锌单晶微管。生长的氧化锌单晶呈端面和侧面呈六角形的中空微管形状。通过制备高质量的尺寸可控的氧化锌单晶微管，研究在表面肌电信号条件下生长氧化锌单晶微管的基本机理和动力学。我们将进行各种测量来表征氧化锌单晶的物理、光学、电学和耦合性质，如光敏性、光致发光、压电性和缺陷/载流子密度。电抽运纵向单模激光器和回音廊模式可调谐滤光器的应用潜力也将被探索。此外，还将研究独立微管的氮气扩散处理，以制备用于电场泵浦发射的p-n结。*该项目致力于与电子和光子学具有很强技术相关性的基础材料研究，并有效地将研究和教育结合在一起。对新型单晶氧化锌中空六方微管材料体系的探索和深入认识，为发展先进的光电子器件提供了可能。该项目为研究生和本科生提供跨学科的研究和教育机会，并积极寻求扩大代表性不足群体成员的研究参与。

This project aims to understand the growth mechanism(s) of single crystal zinc oxide (ZnO) microtubes and their physical and characteristics relevant to device applications. Normally, ZnO single crystals have been fabricated in three forms: bulk crystals, thin films and nanowires/nanorods. Recently, the principal investigators have fabricated ZnO single crystal microtubes using a novel self-encapsulated microwave growth (SEMG) method. The ZnO single crystals are grown in hexagonal hollow microtube shapes with faceted ends and side surfaces. Through fabrication of high quality dimension-controlled ZnO single crystal microtubes, fundamental growth mechanisms and kinetics of ZnO single crystal tubes growth in SEMG conditions will be investigated. A variety of measurements will be conducted to characterize the physical/optical/electrical and coupled properties of the ZnO single crystals such as photosensitivity, photoluminescence, piezoelectricity, & defect/carrier densities. Potential for electric pumped longitudinal single mode laser and whispering gallery mode tunable filter applications will also be explored. Additionally, nitrogen-in-diffusion treatment of freestanding microtubes will be investigated to fabricate p-n junction for electric field pumped emissions. *** The project addresses fundamental materials research with strong technological relevance to electronics and photonics, and effectively integrates research and education. The exploration and further understanding of the novel single crystal ZnO hollow hexagonal microtube materials system may provide the potential for advanced optoelectronic devices. This project provides interdisciplinary research and educational opportunities for graduate and undergraduate students, and actively seeks to broaden research participation by members of underrepresented groups.