Hydrogen released from bulk ZnO single crystals investigated by time-of-flight electron-stimulated desorption

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3505750· OSTI ID:21537944

Dierre, Benjamin; Sekiguchi, Takashi ^[1]; Yuan, Xiaoli ^[1]; Ueda, Kazuyuki ^[2]

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1. Advanced Electronic Materials Center, National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan)
2. Nano High-Tech Research Center, Graduate School of Engineering, Toyota Technological Institute, Nagoya 468-8511 (Japan)

Electron beam (e-beam) irradiation effects on ZnO single crystals have been investigated by using time-of-flight electron-stimulated desorption (TOF-ESD). The samples were irradiated by using a continuous 0.5 or 1.5 keV e-beam, while the TOF-ESD spectra were taken by using a pulsed 0.5 keV e-beam. For both the O-terminated and Zn-terminated surfaces, the major desorption is H{sup +} desorption. The main trend of H{sup +} desorption intensity and evolution as a function of irradiation time is similar for both faces. The H{sup +} peak is much higher after 1.5 keV irradiation than after 0.5 keV irradiation. The intensity of the H{sup +} peak decreases exponentially as a function of irradiation time and partially recovers after the irradiation is stopped. These observations suggest that the main contribution of the H{sup +} desorption is hydrogen released from the dissociation of H-related defects and complexes in the bulk region of the ZnO by e-beam irradiation. This finding can be used to explain the reported ultraviolet degradation of ZnO single crystals under electron irradiation observed by cathodoluminescence. The surfaces play a lesser role for the H{sup +} desorption, as there are differences of the decreasing rate between the two faces and additionally the intensity of the H{sup +} peak for both the unclean O-face and Zn-facesis smaller than that for clean faces. While the H{sup +} desorption is mainly dominated by the bulk region, O{sup +} desorption is more influenced by the surfaces. There are two kinds of O{sup +} desorbed from ZnO having 13.0 {mu}s TOF and 14.2 {mu}s TOF. The O{sup +} desorption depends on the surface polarity, the surface conditions and the energy used for irradiation.

• OSTI ID: 21537944
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 10; Other Information: DOI: 10.1063/1.3505750; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CATHODOLUMINESCENCE
CRYSTAL DEFECTS
DESORPTION
DISSOCIATION
ELECTRON BEAMS
HYDROGEN
HYDROGEN IONS 1 PLUS
IRRADIATION
KEV RANGE 01-10
MONOCRYSTALS
OXYGEN IONS
SEMICONDUCTOR MATERIALS
SPECTRA
SURFACE ENERGY
SURFACE POTENTIAL
SURFACES
TIME-OF-FLIGHT METHOD
ULTRAVIOLET RADIATION
ZINC OXIDES
BEAMS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CRYSTAL STRUCTURE
CRYSTALS
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION
ENERGY
ENERGY RANGE
FREE ENERGY
HYDROGEN IONS
IONS
KEV RANGE
LEPTON BEAMS
LUMINESCENCE
MATERIALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE BEAMS
PHOTON EMISSION
PHYSICAL PROPERTIES
POTENTIALS
RADIATIONS
SORPTION
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
ZINC COMPOUNDS