Recombination dynamics of deep defect states in zinc oxide nanowires

Anno: 2009

Autori: Lettieri S., Santamaria Amato L., Maddalena P., Comini E., Baratto C., Todros S.

Affiliazione autori: 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.

Giornale/Rivista: NANOTECHNOLOGY

Volume: 20 (17)      Da Pagina: 175706  A: 175706

Parole chiavi: ZnO
DOI: 10.1088/0957-4484/20/17/175706

Citazioni: 37
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-04-28
Riferimenti tratti da Isi Web of Knowledge: (solo abbonati)
Link per visualizzare la scheda su IsiWeb: Clicca qui
Link per visualizzare la citazioni su IsiWeb: Clicca qui