Fabrications and Characterizations of ZnO/Zn1-xMgxO Nanorod Quantum Structures
Abstract
Semiconductor nanorod heterostructures open up significant opportunities for fabrication of electronic and photonic nanodevices on single nanorods. The semiconductor nanorod quantum structures with well-defined interfaces are main components for nanoscale resonant tunneling devices, field effect transistors, and light-emitting devices since the nanorod quantum structures (QSs) enable novel physical properties such as quantum confinement and formation of minibands. In particular, spectral wavelength can be tuned by varying the well thickness, and the light emission efficiency is significantly enhanced at room temperature. However, quantum confinement effects in nanowires/nanorod heterostructures have not been easily observed despite recent synthesis of compositionally modulated nanowire superlattices by the vapor liquid solid (VLS) growth process. This may result from the relatively broad heterostructure interfaces caused by realloying of alternating reactants in the metal catalyst during the condensation-precipitation process. In that case, abrupt interfaces can be obtained using our catalyst-free nanorod heteroepitaxial growth technique. This nanorod growth method makes it possible to control the thickness of each layer within the monolayer level by utilizing direct adsorption of atoms on the surface of nanorods. We demonstrated this by the fabrication of ZnO/MgZnO nanorod QSs which exhibit the clear signature of quantum confinement, an increasing blue shift with decreasing layer thickness. In this research, we investigated luminescent characteristics of a single nanorod QS including ZnO/MgZnO coaxial nanorod single-quantum-wells and ZnO/MgZnO nanorod double-quantum-wells using photoluminescence and cathodoluminescence spectroscopy. In addition, we demonstrated nanophotonic switch based on the coupling behavior between optical near-field and ZnO/MgZnO nanorod double-quantum-wells.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 2007
- Accession Number
- ADA474747
Entities
People
- Gyu-chul Yi
Organizations
- Pohang University of Science and Technology