Positron annihilation studies in ZnO nanoparticles

被引：58

作者：

Sharma, S. K. ^{[1
]}

Pujari, P. K. ^{[1
]}

Sudarshan, K. ^{[1
]}

Dutta, D. ^{[1
]}

Mahapatra, M. ^{[1
]}

Godbole, S. V. ^{[1
]}

Jayakumar, O. D. ^{[2
]}

Tyagi, A. K. ^{[2
]}

机构：

[1] Bhabha Atom Res Ctr, Div Radiochem, Bombay 400085, Maharashtra, India

[2] Bhabha Atom Res Ctr, Div Chem, Bombay 400085, Maharashtra, India

来源：

SOLID STATE COMMUNICATIONS | 2009年 / 149卷 / 13-14期

关键词：

Nanoparticles; Zinc oxide; Vacancy; Positron annihilation; SPECTROSCOPY; SURFACES; DEFECTS; SOLIDS;

D O I：

10.1016/j.ssc.2009.01.005

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

We report results on positron annihilation spectroscopic (PAS) studies using lifetime and coincidence Doppler broadening techniques in zinc oxide (ZnO) nanoparticles (4 to 40 nm) synthesized by solid state pyrolytic reaction followed by annealing in the temperature range of 200 degrees C to 800 degrees C. Positron lifetime in the nanoparticles are observed to be higher than bulk lifetime in all the cases. Theoretical calculation of lifetime indicates the presence of either Zn or (Zn, O) vacancy clusters which migrate and anneal out at high temperature. Comparison of ratio spectra from coincidence Doppler broadening measurement and calculated electron momentum distribution indicates the presence of either Zn or (Zn, O) vacancies. In addition, photoluminescence (PL) measurements have been carried out to examine the role of defects on the intensity of emission in the visible region. (C) 2009 Elsevier Ltd. All rights reserved,

引用

页码：550 / 554

页数：5

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