Optical properties of thin films of zinc oxide quantum dots and polydimethylsiloxane: UV-blocking and the effect of cross-linking
2012 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 387, 135-140 p.Article in journal (Refereed) Published
Thin films of polydimethylsiloxane (PDMS) and ZnO quantum dots (QDs) were built up as multilayers by spin-coating. The films are characterized by a UV-blocking ability that increases with increasing number of bilayers. Photoluminescence (PL) emission spectra of the thin films occur at 522 nm, which is the PL wavelength of the ZnO QDs dispersion, but with a lower intensity and a quantum yield (QY) less than 1% that of the dispersion. Cross-linking has introduced new features to the absorption spectra in that the absorption peak was absent. These changes were attributed to the morphological and structural changes revealed by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR), respectively. TEM showed that the ZnO particle size in the film increased from 7 (+/- 2.7) nm to 16 (+/- 7.8) upon cross-linking. The FTIR spectra suggest that ZnO QDs are involved in the cross-linking of PDMS and that the surface of the ZnO QDs has been chemically modified.
Place, publisher, year, edition, pages
2012. Vol. 387, 135-140 p.
Transmission, Absorption, Emission, Structure, Interface
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-104687DOI: 10.1016/j.jcis.2012.07.065ISI: 000309572100015ScopusID: 2-s2.0-84866622544OAI: oai:DiVA.org:kth-104687DiVA: diva2:566785
QC 201211092012-11-092012-11-092012-11-09Bibliographically approved