Hydrogen in bulk and nanoscale ZnO
| Autor: | W. M. Hlaing Oo, Matthew D. McCluskey, S. J. Jokela |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Materials science
Hydrogen Absorption spectroscopy Annealing (metallurgy) Hydrostatic pressure Doping Infrared spectroscopy chemistry.chemical_element Condensed Matter Physics Electronic Optical and Magnetic Materials chemistry Deuterium Chemical physics Molecular vibration Electrical and Electronic Engineering |
| Zdroj: | Physica B: Condensed Matter. :690-693 |
| ISSN: | 0921-4526 |
| Popis: | Zinc oxide (ZnO) is a wide-band gap semiconductor that has attracted resurgent interest as an electronic material for a range of applications. In our work, we have focused on the properties of hydrogen donors in ZnO. In bulk, single-crystal ZnO doped with hydrogen or deuterium, infrared (IR) absorption peaks corresponding to O–H and O–D stretch modes were observed at 3326.3 and 2470.3 cm −1 , respectively, at liquid-helium temperatures. IR spectroscopy using polarized light showed that the O–H dipoles are aligned along an angle 111° to the c -axis. The slight negative shift of the O–H mode as a function of hydrostatic pressure suggests that the hydrogen resides in an anti-bonding orientation. The O–H complexes are unstable, perhaps due to the formation of “hidden” H 2 molecules. As dimensions approach the nanoscale, the vastly increased surface-to-volume ratio leads to interesting phenomena. At moderate annealing temperatures (350 °C), hydrogen interacts with the nanoparticles, resulting in a dramatic increase in electrical conductivity, free-carrier absorption, and IR reflectivity. |
| Databáze: | OpenAIRE |
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