The growth of Co:ZnO/ZnO core/shell colloidal quantum dots:: Changes in nanocrystal size, concentration and dopant coordination

被引：37

作者：

Lommens, Petra ^{[1
]}

Lambert, Karel ^{[1
]}

Loncke, Frank ^{[2
]}

De Muynck, David ^{[1
]}

Balkan, Timucin ^{[1
]}

Vanhaecke, Frank ^{[1
]}

Vrielinck, Henk ^{[2
]}

Callens, Freddy ^{[2
]}

Hens, Zeger ^{[1
]}

机构：

[1] Univ Ghent, Dept Analyt Chem, B-9000 Ghent, Belgium

[2] Univ Ghent, Dept Solid State Sci, B-9000 Ghent, Belgium

来源：

CHEMPHYSCHEM | 2008年 / 9卷 / 03期

关键词：

colloidal quantum dots; magnetic semiconductors; doping; EPR spectroscopy; UV/Vis spectroscopy;

D O I：

10.1002/cphc.200700753

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：

We report a synthesis route for the growth of Co:ZnO/ZnO core/shell quantum dots. This procedure consists of successive steps, comprising the addition of diluted precursor salt solutions, and heat treatment at 50 degrees C. By deriving a relation between the extinction coefficient at 250 nm and the nanocrystal diameter, we are able to monitor changes in quantum dot concentration during shell growth. We found that a mechanism based on the nucleation of new particles after salt addition and subsequent Ostwald ripening during the heat treatment is responsible for the shell growth. Based on ligand-field absorption spectroscopy, we demonstrate that the Co2+ ions adsorbed at the surface of Co:ZnO quantum dots are incorporated inside the ZnO shells. Finally, EPR spectroscopy indicates that the surface-adsorbed Co2+ ions can be incorporated as substitutional as well as interstitial Co2+ ions.

引用

页码：484 / 491

页数：8

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