6533b860fe1ef96bd12c3921

RESEARCH PRODUCT

Photoluminescence transient study of surface defects in ZnO nanorods grown by chemical bath deposition

Isodiana CrupiE. G. BarbagiovanniGiorgia FranzòV. StranoSalvo Mirabella

subject

PhotoluminescencePhysics and Astronomy (miscellaneous)Analytical chemistryPhotovoltaic applicationFOS: Physical scienceschemistry.chemical_elementNanorodOxygen vacancieSettore ING-INF/01 - ElettronicaOxygensymbols.namesakeMesoscale and Nanoscale Physics (cond-mat.mes-hall)ultravioletSurface defect stateDepositionPhotoluminescenceChemical-bath depositionTransient studies Surface defectsPhysicsCondensed Matter - Mesoscale and Nanoscale PhysicsFermi levelDeep-level defectBand bendingnanowireschemistryZinc oxide Ambient environmentsymbolsNanorodPhotoluminescence intensitiefilmsTransient (oscillation)Resistance measurementIntensity (heat transfer)Chemical bath deposition

description

Two deep level defects (2.25 and 2.03 eV) associated with oxygen vacancies (Vo) were identified in ZnO nanorods (NRs) grown by low cost chemical bath deposition. A transient behaviour in the photoluminescence (PL) intensity of the two Vo states was found to be sensitive to the ambient environment and to NR post-growth treatment. The largest transient was found in samples dried on a hot plate with a PL intensity decay time, in air only, of 23 and 80 s for the 2.25 and 2.03 eV peaks, respectively. Resistance measurements under UV exposure exhibited a transient behaviour in full agreement with the PL transient, indicating a clear role of atmospheric O-2 on the surface defect states. A model for surface defect transient behaviour due to band bending with respect to the Fermi level is proposed. The results have implications for a variety of sensing and photovoltaic applications of ZnO NRs. (C) 2015 AIP Publishing LLC.

yearjournalcountryeditionlanguage
2015-01-01Applied Physics Letters
https://doi.org/10.1063/1.4914067