Point defects in ZnO crystals grown by various techniques

14th International Workshop on Slow Positron Beam Techniques & Applications

íek, J.^1 ; Vlek, M.^1 ; Hruka, P.^1 ; Luká, F.^1 ; Melikhova, O.^1 ; Anwand, W.^2 ; Selim, F.^3 ; Hugenschmidt, Ch^4 ; Egger, W.^5

Faculty of Mathematics and Physics, Charles University, V Holeovikách 2, Praha 8

18000, Czech Republic^1

Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, Dresden

01328, Germany^2

Center for Photochemical Sciences, Bowling Green State University, Bowling Green

OH

43403, United States^3

Technical University München, Lichtenbergstraße 1, Garching

85747, Germany^4

Bundeswehr München, Werner-Heisenberg-Weg 39, Neubiberg

85577, Germany^5

关键词: Back diffusion;    Chemical Vapour Transport;    Density of defects;    Hydrothermally;    Positron lifetime spectroscopy;    Seeded chemical vapor transports;    Slow positron;    ZnO crystals;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/791/1/012017/pdf
DOI  :  10.1088/1742-6596/791/1/012017

来源: IOP

【 摘 要 】

In the present work point defects in ZnO crystals were characterized by positron lifetime spectroscopy combined with back-diffusion measurement of slow positrons. Defects in ZnO crystals grown by various techniques were compared. Hydrothermally grown ZnO crystals contain defects characterized by lifetime of ≈181 ps. These defects were attributed to Zn vacancies associated with hydrogen. ZnO crystals prepared by other techniques (Bridgman, pressurized melt growth, and seeded chemical vapour transport) exhibit shorter lifetime of ≈165 ps. Positron back-diffusion studies revealed that hydrothermally grown ZnO crystals contain higher density of defects than the crystals grown by other techniques. The lowest concentration of defects was detected in the crystal grown by seeded chemical vapor transport.