Luminescent vacuum ultraviolet spectroscopy of Cr3+ ions in nanostructured aluminum oxide / Pustovarov V. A.,Kortov V. S.,Zvonarev S. V.,Medvedev A. I. // JOURNAL OF LUMINESCENCE. - 2012. - V. 132, l. 11. - P. 2868-2873.

ISSN/EISSN:

0022-2313 / нет данных

Type:

Article

Abstract:

Impurity Cr3+ centers in submicron and nanostructured Al2O3 crystals of different phase compositions at temperatures of 300 and 7.5 K were studied by a luminescent vacuum ultraviolet (VUV) spectroscopy method. Photoluminescence (PL) spectra and the energies of E-2, T-4(2), and T-4(1) excited states of Cr3+ ion depend on the type of crystalline samples phase. The PL excitation spectrum of R-line in alpha-Al2O3 nanoscale crystals is formed by intracenter transitions (2.5-5.5 eV region), by charge transfer band (6.9 eV) and by effective formation of impurity-bound excitons (9.0 eV region). Such impurity-bound excitons correspond to O(2)p -> Al(3)s electron transition in surroundings of an impurity Cr3+ center. The efficiency of impurity-bound excitons formation decreases with the increase of the grain size above 100 nm. The size dependence is noticeably shown in PL excitation spectra in VUV region. Excitons bound to impurity centers do not appear in nanostructured delta+theta-Al2O3 crystals. The effect of the electron excitation multiplication is observed distinctly in nanostrucured alpha-Al2O3 at an excitation energy above 19 eV (more than 2E(g)). (C) 2012 Elsevier B.V. All rights reserved.

Author keywords:

Aluminum oxide; Nanoscale crystals; Impurity center; Photoluminescence spectroscopy; Bound exciton ELECTRONIC EXCITATIONS; SYNCHROTRON-RADIATION; AL2O3; MULTIPLICATION; CRYSTALS; CORUNDUM; DEFECTS

DOI:

10.1016/j.jlumin.2012.06.001

Web of Science ID:

ISI:000308627400009

Соавторы в МНС:

Другие поля

Поле	Значение
Month	NOV
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	ELECTRONIC EXCITATIONS; SYNCHROTRON-RADIATION; AL2O3; MULTIPLICATION; CRYSTALS; CORUNDUM; DEFECTS
Research-Areas	Optics
Web-of-Science-Categories	Optics
Author-Email	vpustovarov@bk.ru
Funding-Acknowledgement	Grant of Russian Federal Program ``Industry of Nanosystems and Materials{''} {[}02.513.11.3216]; HASYLAB, DESY {[}II-20080019]
Funding-Text	The authors are grateful to Yu.A. Kotov and V.I. Ivanov for the arrangements made for preparation and some characterization of the nanostructured samples in Institute of Electrophysics of Ural Branch RAS. This study was supported by Grant of Russian Federal Program ``Industry of Nanosystems and Materials{''} (State contract no. 02.513.11.3216) and HASYLAB, DESY (Project no. II-20080019).
Number-of-Cited-References	26
Usage-Count-Since-2013	21
Journal-ISO	J. Lumines.
Doc-Delivery-Number	003QW