Fast Monolayer Adsorption and Slow Energy Transfer in CdSe Quantum Dot Sensitized ZnO Nanowires
2013 (English)In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 117, no 29, 5919-5925 p.Article in journal (Refereed) Published
A method for CdSe quantum dot (QD) sensitization of ZnO nanowires (NW) with fast adsorption rate is applied. Photoinduced excited state dynamics of the quantum dots in the case of more than monolayer coverage of the nanowires is studied. Transient absorption kinetics reveals an excitation depopulation process of indirectly attached quantum dots with a lifetime of similar to 4 ns. Photoluminescence and incident photon-to-electron conversion efficiency show that this process consists of both radiative e-h recombination and nonradiative excitation-to-charge conversion. We argue that the latter occurs via interdot energy transfer from the indirectly attached QDs to the dots with direct contact to the nanowires. From the latter, fast electron injection into ZnO occurs. The energy transfer time constant is found to be around 5 ns.
Place, publisher, year, edition, pages
American Chemical Society , 2013. Vol. 117, no 29, 5919-5925 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-97671DOI: 10.1021/jp3098632ISI: 000322503200009OAI: oai:DiVA.org:liu-97671DiVA: diva2:649974
Funding Agencies|Knut and Alice Wallenberg Foundation||Crafoord Foundation||Swedish Energy Agency||2013-09-192013-09-192013-09-19