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Enhanced ultraviolet emission and optical properties in polyvinyl pyrrolidone surface modified ZnO quantum dots.

Authors :
Yang, C. L.
Wang, J. N.
Ge, W. K.
Guo, L.
Yang, S. H.
Shen, D. Z.
Source :
Journal of Applied Physics; 11/1/2001, Vol. 90 Issue 9, p4489, 5p, 5 Graphs
Publication Year :
2001

Abstract

Optical properties of ZnO quantum dots (QDs) capped with polyvinyl pyrrolidone (PVP) molecules have been investigated. It is demonstrated that surface modification by PVP can dramatically change the emission spectra of the ZnO QDs. At the optimized condition with a PVP/Zn[sup 2+] ratio of 3:5, the photoluminescence (PL) spectrum of ZnO QDs shows a strong ultraviolet (UV) emission while the low energy green emission is fully quenched. This is a result of the surface passivation of the ZnO QDs by the PVP molecules. The origin of the green emission is attributed to the surface states associated with oxygen vacancies. Temperature and excitation power dependent PL studies suggest that the UV emission is associated with localized states. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00218979
Volume :
90
Issue :
9
Database :
Complementary Index
Journal :
Journal of Applied Physics
Publication Type :
Academic Journal
Accession number :
5356444
Full Text :
https://doi.org/10.1063/1.1406973