Jana, Sunirmal and Biswas, Prasanta Kumar (1997) Optical characterization of in-situ generated Cu2O excitons in solution derived nano-zirconia film matrix. Materials Letters, 32 (4). pp. 263-270. ISSN 0167-577X

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Abstract

Cu2O excitons were generated in-situ in a nano-zirconia film matrix on silica glass substrate from the precursor solution containing Cu(II) nitrate trihydrate and zirconium oxychloride octahydrate. The films were annealed in the temperature range 200-1200 degrees C and characterized by transmission electron microscopy (TEM), UV-VIS-NIR and fluorescence spectroscopy. In the UV-VIS spectra of the films most of the UV and visible bands shifted towards longer wavelengths with increasing annealing temperature and the corresponding Cu2O microcrystallite size was evaluated from the shifting of the UV bands (271-371 nm). Wannier hydrogen-like excitonic transitions, e.g., blue, green, yellow series of Cu2O excitons were observed in the visible region. Excitation dependent fluorescence bands were observed in the visible region and the 400 nm excitation depicted two distinct fluorescence bands in the green (similar to 525 nm) and red (similar to 630 nm) regions. The intensity ratios of green and red fluorescences and vice versa were found to be dependent on the microcrystallite size. Tentative band assignments have been proposed from the excitonic absorption and fluorescence bands.

Item Type:	Article
Uncontrolled Keywords:	zirconium oxychloride octahydrate; nano-zirconia; films; Cu2O exciton; UV-VIS-NIR spectroscopy; fluorescence spectroscopy; transmission electron microscopy; microcrystallite
Subjects:	Microstructure and Characterization Engineering Materials
Divisions:	Sol Gel
Depositing User:	Bidhan Chaudhuri
Date Deposited:	18 Jul 2012 11:41
Last Modified:	17 Sep 2015 06:44
URI:	http://cgcri.csircentral.net/id/eprint/1618

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