Size dependent fluorescence spectroscopy of nanocolloids of ZnO


Autoria(s): Litty, Irimpan; Nampoori, V P N; Radhakrishnan, P; Deepthy, A; Bindu, Krishnan
Data(s)

14/12/2011

14/12/2011

2007

Resumo

In this article we present size dependent spectroscopic observations of nanocolloids of ZnO. ZnO is reported to show two emission bands, an ultraviolet (UV) emission band and another in the green region. Apart from the known band gap 380 nm and impurity 530 nm emissions, we have found some peculiar features in the fluorescence spectra that are consistent with the nanoparticle size distribution. Results show that additional emissions at 420 and 490 nm are developed with particle size. The origin of the visible band emission is discussed. The mechanism of the luminescence suggests that UV luminescence of ZnO colloid is related to the transition from conduction band edge to valence band, and visible luminescence is caused by the transition from deep donor level to valence band due to oxygen vacancies and by the transition from conduction band to deep acceptor level due to impurities and defect states. A correlation analysis between the particle size and spectroscopic observations is also discussed.

Identificador

J. Appl. Phys. 102, 063524 (2007)

http://dyuthi.cusat.ac.in/purl/2639

doi:10.1063/1.2778637

Idioma(s)

en

Publicador

American Institute of Physics

Palavras-Chave #II-VI semiconductors #Nanocrystals #Colloids #Electron states #collective excitations in multilayers #quantum wells #mesoscopic #nanoscale systems
Tipo

Working Paper