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Title: High pressure studies of luminescence efficiency and lifetime in La/sub 2/O/sub 2/S:Eu and Y/sub 2/O/sub 2/S:Eu

Journal Article · · J. Chem. Phys.; (United States)
OSTI ID:5668310

The effect of pressure to 120 kbars has been measured on the luminescence efficiency of La/sub 2/O/sub 2/S:Eu and Y/sub 2/O/sub 2/S:Eu in concentrations from 0.1% to 3% europium. Lifetimes were also measured for the lanthanum compounds. For La/sub 2/O/sub 2/S:Eu the emissions from /sup 5/D/sub 0/ and /sup 5/D/sub 1/ decreased in intensity with increasing pressure; the very weak /sup 5/D/sub 2/ emission increased by a large factor, leveled in the region approx.40--80 kbars and decreased at the highest pressure; the emission fro /sup 5/D/sub 3/ appeared at about 50--60 kbars and increased rapidly in intensity. These results could be explained essentially quantitatively in terms of the analyses of Struck and Fonger and the observed shift to higher energy of the charge transfer absorption. Increased concentration of dopant dampened the effect of pressure. This is also consistent with the analysis. In addition, the behavior of the lifetime with pressure confirmed the above results and showed that no significant new radiationless paths appear at high pressure. There were also large pressure effects in Y/sub 2/O/sub 2/S:Eu. While these differed quantitatively from the effects in La/sub 2/O/sub 2/S:Eu they could be explained in terms of the analysis and the difference in location of the charge transfer peak and its shift with pressure.

Research Organization:
School of Chemical Sciences and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
OSTI ID:
5668310
Journal Information:
J. Chem. Phys.; (United States), Vol. 72:6
Country of Publication:
United States
Language:
English