NER: Feasibility Studies on ZnO Nanostructures And Their Device Applications

PROPOSAL NO.: 0103096 PRINCIPAL INVESTIGATOR: Lu, Yicheng INSTITUTION NAME: Rutgers University New Brunswick TITLE: NER: Feasibility Studies on ZnO Nanostructures And Their Device Applications This proposal addresses the exploratory research on zinc oxide (ZnO) based nanoscale structures and feasibility study of their device applications. ZnO is a multifunctional material possessing unique electrical, optical, acoustical, and mechanical properties. Semiconductor ZnO has a wide and direct energy bandgap (~3.3eV). ZnO can be grown at low temperatures, in contrast with the other wide bandgap materials, such as GaN and SiC. Its ternary compounds, formed by alloying ZnO with CdO and MgO, permit bandgap tuning from ~2.8 eV to ~4 eV. Doped ZnO ternaries can be made magnetic or ferroelectric, extending its applications beyond the traditional semiconductor confines. In this exploratory research, we will study growth mechanisms and conduct substrate engineering for selective growth of ZnO nanotips and nanotip arrays on various substrates, including R-plane sapphire, Si, silicon-on-sapphire (SOS), and GaN-on-sapphire. Feasibility studies of ZnO nanotip applications will focus on field-emission, two-dimensional photonic bandgap (PBG), and fine instrumentation such as atomic force microscopy and scanning tunneling optical microscopy. We will also explore the feasibility to form CdO quantum dots in ZnO using the activated alloy phase segregation mechanism, which may be proved as a viable alternative to the Stranski-Krastanov mechanism. These quantum dots have potential applications in UV lasers and integrated UV optoelectronic chips. The proposed work will extend the research on nanoscale structures and devices into the field of wide bandgap semiconductor nanoscale science and engineering. The research and development of nanoscale structures in ZnO and its ternaries will lead to a fundamentally new class of devices, which integrate multi-phenomena and posses unprecedented multi-functional characteristics.