Czochralski Growth and Optical Properties οf (Lu_{x}Gd_{1-x})_2SiO_5 Solid Solution Crystals Single Doped with Sm^{3+} and~Dy^{3+}

Abstract

Solid solution crystals (LuxGd1−x)2SiO5 single doped with Sm 3+ and Dy were grown by the Czochralski method. Segregation coe cients Lu/Gd, melting temperatures and structures of solid solution crystals were determined for 0.15 ≤ x ≤ 0.8. It was found that for x ≥ 0.17 the crystals belong to the monoclinic system within a space group C2/c and their melting temperature diminishes monotonously from 1990 ◦C to 1780 ◦C when x decreases from 0.8 to 0.15. Disparity of ionic radii of Lu and Gd induces structural disorder that brings about an inhomogeneous broadening of spectral lines in absorption and emission spectra of incorporated luminescent Sm and Dy ions. Optical properties of obtained crystals were determined based on results of measurement of absorption and emission spectra and luminescence decay curves. Spectroscopic investigation revealed that Sm doped crystals show intense emission distributed in the visible-near infrared region with the most intense band centred at 605 nm and characterized by a branching ratio of 0.43. Emission spectrum of Dy doped crystals is dominated by a band centred at 575 nm and characterized by a branching ratio of 0.58. It has been concluded that the systems under study are potential laser materials able to generate visible emission upon GaN/InGaN laser diode pumping.