Size-Dependent Optical Properties of Colloidal ZnO Nanoparticles Charged by Photoexcitation

被引:68
作者
Stroyuk, Oleksandr L. [1 ]
Dzhagan, Volodymyr M. [2 ]
Shvalagin, Vitaliy V. [1 ]
Kuchmiy, Stepan Ya. [1 ]
机构
[1] Natl Acad Sci Ukraine, LV Pysarzhevskiy Inst Phys Chem, UA-03028 Kiev, Ukraine
[2] Natl Acad Sci Ukraine, VE Lashkaryov Inst Semicond Phys, UA-03028 Kiev, Ukraine
关键词
NANOCRYSTALLINE ZNO; ZINC-OXIDE; N-TYPE; QUANTUM DOTS; SEMICONDUCTOR; PARTICLES; EMISSION; PHOTOLUMINESCENCE; PHOTOCHEMISTRY; FLUORESCENCE;
D O I
10.1021/jp908879h
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The above-bandgap illumination of colloidal ZnO natioparticles (NPs) in ethanol solutions is found to lead to reversible shifts of the absorption and photoluminescence (PL) excitation spectra, indicating charging of the nanoparticles with electrons. A rapid drop of deep-level PL intensity at the early stage of illumination is observed simultaneously with the splitting-off and growth of a new red-shifted near-band-edge PL band. Such a splitting of the near-bandgap PL band under illumination is observed for the first time and corroborates with the previous assumptions about the behavior of the NP ensemble emission upon gradual NPs' charging with electrons. The possible relation between the new PL band and photoinduced charging of NPs with excess electrons is discussed on the basis of the dependence of the PL spectrum evolution and absorption band shift relaxation on the NP size and controllable access of oxygen during illumination.
引用
收藏
页码:220 / 225
页数:6
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