Growth, structure and optical characterization of new Pr3+-doped LaGaGe2O7 and LaGa0.6Al0.4Ge2O7 single crystals

• Published in: Journal of alloys and compounds Vol. 1002; p. 175301
• Main Authors: Cassouret, Florent, Sattayaporn, Suchinda, Loiseau, Pascal, Delgado, Teresa, Chaboud, Mathilde, Debray, Jerome, Segonds, Patricia, Aka, Gerard
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2024
• Subjects: Crystal growth; Luminescence; Optical materials; Optical spectroscopy; Oxide materials; Crystal growth; Optical spectroscopy; Optical materials; Oxide materials; Luminescence
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.175301

In this work, a new crystal belonging to the germanate family: LaGaGe2O7 (or LGGO) doped with trivalent Praseodymium (Pr) ion is studied. We report the first single crystal growth of this material using the Czochralski method. The spectroscopic properties including absorption and emission cross-sections of praseodymium in this new matrix are measured, as well as the refractive index along the dielectric axes. This material exhibits very high emission cross sections of 38, 20, and 16 10−20 cm2 at 746 nm, 646 nm and 620 nm, respectively. Some persistent luminescence is observed in Pr:LGGO after UV irradiation at 254 nm. To reduce the phenomenon, the solid solution LaGa1-xAlxGe2O7 (0 ≤ x ≤ 1) is considered. Thermoluminescence experiments show that a substitution of 40 % of gallium by aluminium in the crystal structure allows to suppress this persistent luminescence phenomenon.
•First Czochralski growth of Pr-doped LaGaGe2O7 single crystal is demonstrated.•The substitution of Ga by Al in the crystal doesn’t alter the spectroscopic properties.•The emission cross sections were measured over 10−19 cm2 in the red and orange range.•The substitution of 40 % of Ga by Al suppresses persistent luminescence of the crystal.