Ultrafast relaxation dynamics of charge carriers relaxation in ZnO nanocrystalline thin films
2004 (English)In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 387, no 03-jan, 176-181 p.Article in journal (Refereed) Published
Ultrafast spectroscopy has been used to study the relaxation processes of charge carriers in ZnO nanocrystalline thin films. A broad red-IR absorption band linked to shallowly trapped electrons was observed by spectroelectrochemical measurements. Femtosecond transient absorption data revealed multiexponential decays of the charge carriers with time constants ranging from 1 to 400 ps. The decay profile of the signal shows a probe wavelength dependence. This effect is assigned to the trapping (localisation) of nonequilibrium charge carriers which occurs on a time scale of similar to1 ps. The recombination of shallowly trapped electrons with deeply trapped holes, determined by single-photon counting, mainly occurs in 400 ps.
Place, publisher, year, edition, pages
2004. Vol. 387, no 03-jan, 176-181 p.
diffuse-reflectance spectroscopy, semiconductor nanoparticles, femtosecond, surface, size, photocatalysis, nanoclusters, photophysics, colloids
IdentifiersURN: urn:nbn:se:kth:diva-23265DOI: 10.1016/j.cplett.2004.01.106ISI: 000220272500031OAI: oai:DiVA.org:kth-23265DiVA: diva2:341963
QC 201005252010-08-102010-08-10Bibliographically approved