Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7908691 | Optical Materials | 2016 | 6 Pages |
Abstract
Tetragonal CsScF4 crystals doped with (5Â at.%) Er and Er/Yb (0.5Â at.%/5Â at.%) are grown and their crystal structure is determined to belong to Pmmn space group. Er and Yb ions are shown to occupy distorted octahedral Sc sites with the center of inversion. Bright visible upconversion luminescence was observed under 970-980Â nm pumping with red (4F9/2), yellow (4S3/2) and green (2H11/2) bands of comparable intensity. UCL tuning curves maximize at 972Â nm (CSF:Er) and at 969.7Â nm (CSF:Er,Yb) pumping wavelengths. Different ratios between yellow-green and red luminescence intensities in CSF:Er and CSF:Er, Yb are explained by contribution of cross-relaxation in CSF:Er UCL. UC in CSF:Er is a three stage process while UC in CSF:Er, Yb is a two stage process. The peculiarities of power dependences are explained by the power-dependent repopulation between starting levels of UC.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
D.A. Ikonnikov, V.N. Voronov, M.S. Molokeev, A.S. Aleksandrovsky,