Luminescence of impurity-bound excitons in Li6GdB3O9:Ce3+ single crystals / Ogorodnikov Igor N.,Pustovarov Vladimir A. // JOURNAL OF PHYSICS-CONDENSED MATTER. - 2012. - V. 24, l. 40.

ISSN/EISSN:

0953-8984 / нет данных

Type:

Article

Abstract:

The anomalous (tau < 10 ns) luminescence of wide bandgap crystals of lithium-gadolinium orthoborate Li6GdB3O9 doped with trivalent cerium ions, has been revealed for the first time and investigated through the low-temperature time-resolved vacuum ultraviolet synchrotron spectroscopy. It was shown that the optical transitions at 6.2 eV are due to electron transfer from the ground 4f(1) states of Ce3+ ion onto the autoionized states near the conduction band bottom of a crystal. These transitions lead to the formation of impurity-bound excitons in the form of correlated electron-hole pair, in which the hole component is localized at 4f-level of the cerium ion and an electron component is located at the conduction band bottom in the attractive potential of this hole. It is established that the direct radiative recombination of the cerium impurity-bound exciton leads to a fast broadband emission at 4.25 eV. The energy threshold for creation of the impurity-bound excitons was determined on the basis of the obtained spectroscopic data. We calculated the H(k) functions of distribution of the elementary relaxations over the reaction rate constants and explained on this basis the decay kinetics and quenching processes, not only for the anomalous emission at 4.25 eV, but for the ordinary 5d-4f luminescence at 3.0 eV in Ce3+ ions. The paper discusses the decay channels for the impurity-bound excitons and their influence on the decay kinetics and spectra of luminescence in Li6GdB3O9 crystals.

Author keywords:

STIMULATED RECOMBINATION PROCESSES; ZINC METAPHOSPHATE GLASSES; LI6GD(BO3)(3)/CE3+ CRYSTALS; ANOMALOUS EMISSION; ENERGY-TRANSFER; SPECTROSCOPY; CE3+; SCINTILLATION; GROWTH

DOI:

10.1088/0953-8984/24/40/405902

Web of Science ID:

ISI:000309050700017

Соавторы в МНС:

Другие поля

Поле	Значение
Month	OCT 10
Publisher	IOP PUBLISHING LTD
Address	TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
Language	English
Article-Number	405902
Keywords-Plus	STIMULATED RECOMBINATION PROCESSES; ZINC METAPHOSPHATE GLASSES; LI6GD(BO3)(3)/CE3+ CRYSTALS; ANOMALOUS EMISSION; ENERGY-TRANSFER; SPECTROSCOPY; CE3+; SCINTILLATION; GROWTH
Research-Areas	Physics
Web-of-Science-Categories	Physics, Condensed Matter
Author-Email	i.n.ogorodnikov@gmail.com
ResearcherID-Numbers	Ogorodnikov, Igor/B-4162-2011
ORCID-Numbers	Ogorodnikov, Igor/0000-0002-4700-2340
Funding-Acknowledgement	HASYLAB DESY {[}II-20080019]
Funding-Text	The authors are grateful to A V Tolmachev, and R P Yavetskiy for providing the crystals grown for the investigation. The work was supported partially by HASYLAB DESY, project no. II-20080019 (SUPERLUMI station, beamline I).
Number-of-Cited-References	32
Usage-Count-Since-2013	10
Journal-ISO	J. Phys.-Condes. Matter
Doc-Delivery-Number	009UM