Photoinduced Enhancement of Photoluminescence of Colloidal II-VI Nanocrystals in Polymer Matrices

Nanomaterials

Oleksandr Stroyuk¹  Oleksandr Selyshchev²  Oleksandra Raievska²  DietrichR. T. Zahn²  Olga Kapush³  Oksana Isaieva³  Mykhailo Valakh³  Volodymyr Dzhagan³  Volodymyr Yukhymchuk³ 

[1] Forschungszentrum Julich GmbH, Helmholtz-Institut Erlangen Nürnberg für Erneuerbare Energien (HI ERN), Immerwahrstr. 2, 91058 Erlangen, Germany;Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany;V. Lashkaryov Institute of Semiconductors Physics, National Academy of Sciences of Ukraine, 01601 Kyiv, Ukraine;

关键词: colloidal quantum dots;    CdSe/CdS;    CdSe/ZnS;    photo-activation;    photo-brightening;   

DOI  :  10.3390/nano10122565

来源: DOAJ

【 摘 要 】

The environment strongly affects both the fundamental physical properties of semiconductor nanocrystals (NCs) and their functionality. Embedding NCs in polymer matrices is an efficient way to create a desirable NC environment needed for tailoring the NC properties and protecting NCs from adverse environmental factors. Luminescent NCs in optically transparent polymers have been investigated due to their perspective applications in photonics and bio-imaging. Here, we report on the manifestations of photo-induced enhancement of photoluminescence (PL) of aqueous colloidal NCs embedded in water-soluble polymers. Based on the comparison of results obtained on bare and core/shell NCs, NCs of different compounds (CdSe, CdTe, ZnO) as well as different embedding polymers, we conclude on the most probable mechanism of the photoenhancement for these sorts of systems. Contrary to photoenhancement observed earlier as a result of surface photocorrosion, we do not observe any change in peak position and width of the excitonic PL. Therefore, we suggest that the saturation of trap states by accumulated photo-excited charges plays a key role in the observed enhancement of the radiative recombination. This suggestion is supported by the unique temperature dependence of the trap PL band as well as by power-dependent PL measurement.

【 授权许可】

Unknown