Recombination dynamics of deep defect states in zinc oxide nanowires
Year: 2009
Authors: Lettieri S., Santamaria Amato L., Maddalena P., Comini E., Baratto C., Todros S.
Autors Affiliation: CNR-INFM Coherentia, I-80126 Napoli, Italy;
Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy;
CNR-INFM SENSOR, Brescia, Italy
Abstract: The recombination dynamics of defect states in zinc oxide nanowires has been studied by developing a general expression for time-resolved photoluminescence intensity based on a second-order approximation for the radiative and non-radiative recombination rates. The model allows us to determine the parameters that characterize the recombination from deep defect states (defect concentration, unimolecular lifetime and bimolecular coefficient) through multi-fitting analysis of time-resolved photoluminescence measurements. Analyses conducted on zinc oxide nanowires gave deep state concentrations of the order of 10(18) cm(-3) and unimolecular lifetimes and bimolecular recombination coefficient comparable to those typical of interband recombination in direct gap semiconductors. The consistency of a \’two-channel decay\’ model (double exponential decay) has been tested by means of a similar analysis procedure. The results suggest that double exponential fitting of time-resolved photoluminescence data of zinc oxide nanowires may be just a mere phenomenological tool which does not reflect the real recombination dynamics of the visible emission band.
Journal/Review: NANOTECHNOLOGY
Volume: 20 (17) Pages from: 175706 to: 175706
KeyWords: ZnODOI: 10.1088/0957-4484/20/17/175706Citations: 38data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-12-01References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here