Nanocomposites and nanomaterials

Influence of different polymers on photoluminescence of colloidal ZnO nanocrystals
Isaieva O.F.1, Dzhagan V.M.1, Selyshchev O.2, Toma M.3, Gule E.G.1, Yukhymchuk V.O.1, Valakh M.Ya.1, and Zahn D.R.T.2
1 V. Lashkaryov Institute of Semiconductors Physics, National Academy of Sciences of Ukraine, Kyiv, Ukraine. 
E-mail: dzhagan@isp.kiev.ua
2 Semiconductor Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany.
3 Babes-Bolyai University, Physics Faculty, M. Kogalniceanu 1, 400084, Cluj-Napoca, Romania.

Embedding NCs in polymer matrices is a way to protect NCs from degradation and to tailor NC properties. Investigation of luminescent NCs in transparent polymers is important due to their perspective applications in photonics and bio-imaging, while NCs in conductive polymers can be promising for photovoltaics, electroluminescence, and photodetectors [1]. Here, we investigate the effects of embedding the ex-situ synthesized colloidal ZnO NCs [2] in different water-soluble polymers, such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), gelatine, and PEDOT:PSS. In addition to recording the spectral and intensity changes in the NC PL spectrum, caused by polymer, we infer possible recombination mechanisms of the NC PL and ways of the interaction between NCs and polymer. The common major effect of PVP, PEG, and PVA is suppression of defect- related PL band (DPL), although at low NC loading the effect of these polymers is more different from each other than at high loading. Gelatine caused unexpectedly quenching of both PL excitonic (EPL) and DPL. The effect of PEDOT:PSS is relatively weak, as for conductive polymer, although distinct indications of structural and electronic changes in the polymer are found in Raman and XPS spectra 

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2.	Panasiuk, Y. V. V; Raevskaya, O. E. E.; Stroyuk, O. L. L.; Kuchmiy, S. Y. Y.; Dzhagan, V. M. M.; Hietschold, M.; Zahn, D. R. T. Colloidal ZnO Nanocrystals in Dimethylsulfoxide: A New Synthesis, Optical, Photo- and Electroluminescent Properties // Nanotechnology.-2014.-25.-P. 075601.