ZnO Luminescence and scintillation studied via photoexcitation, X-ray excitation and gamma-induced positron spectroscopy
- Bowling Green State Univ., OH (United States). Dept. of Physics and Astronomy
- Bowling Green State Univ., OH (United States). Dept. of Physics and Astronomy
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Institute of Radiation Physics
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Institute of Radiation Physics
- Bowling Green State Univ., OH (United States). Center for Photochemical Sciences
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Institute of Radiation Physics; Technische Universität Dresden, Dresden,(Germany)
- Martin-Luther University, Halle (Germany). Dept. of Physics
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Institute of Radiation Physics; Technische Universität Dresden, Dresden,(Germany)
- Bowling Green State Univ., OH (United States). Dept. of Physics and Astronomy; Bowling Green State Univ., OH (United States). Center for Photochemical Sciences
The luminescence and scintillation properties of ZnO single crystals were studied by photoluminescence and X-ray-induced luminescence (XRIL) techniques. XRIL allowed a direct comparison to be made between the near-band emission (NBE) and trap emissions providing insight into the carrier recombination efficiency in the ZnO crystals. It also provided bulk luminescence measurements that were not affected by surface states. The origin of a green emission, the dominant trap emission in ZnO, was then investigated by gamma-induced positron spectroscopy (GIPS) - a unique defect spectroscopy method that enables positron lifetime measurements to be made for a sample without contributions from positron annihilation in the source materials. The measurements showed a single positron decay curve with a 175 ps lifetime component that was attributed to Zn vacancies passivated by hydrogen. Both oxygen vacancies and hydrogen-decorated Zn vacancies were suggested to contribute to the green emission. By combining scintillation measurements with XRIL, the fast scintillation in ZnO crystals was found to be strongly correlated with the ratio between the defect luminescence and NBE. This study reports the first application of GIPS to semiconductors and it reveals the great benefits of the XRIL technique for the study of emission and scintillation properties of materials.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1624847
- Journal Information:
- Scientific Reports, Vol. 6, Issue 1; ISSN 2045-2322
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
The influence of processing conditions on point defects and luminescence centers in ZnO
Origin of green luminescence in hydrothermally grown ZnO single crystals