Suchergebnisse

The work was supported by the ERDF funding in Estonia granted to the Center of Excellence TK141 "Advanced materials and high-technology devices for sustainable energetics, sensorics and nanoelec-tronics" (project No. 2014-2020.4.01.15-0011). Partial support of the projects from the Ministry of Education, Youth and Sports of the Czech Republic no. LO1409, LM2015088 and CZ.02.1.01/0.0/0.0/16 013/ 0001406 is also gratefully acknowledged. ; Temperature dependences of the photoluminescence and X-ray excited luminescence intensity and thermally stimulated luminescence glow curves are measured in the 4.2–300 K temperature range for the undoped and Ce3+ - doped Gd3(Ga,Al)5O12 crystals. The conclusion is made that no low-temperature quenching of the Ce3+ - related photoluminescence takes place. In both the undoped and the Ce3+ - doped crystals, temperature dependences of the X-ray excited recombination luminescence intensity correlate with the position and shape of thermally stimulated luminescence glow curve peaks of the hole origin. Low-temperature quenching of the X-ray excited luminescence in these crystals is explained by the fact that at low temperatures, free holes are trapped at oxygen ions while electrons are trapped at various intrinsic defects. In Ce3+ - doped Gd3(Ga,Al)5O12 crystals, thermally stimulated release of the trapped holes and electrons and their subsequent recombination at Ce3+ ions result in the enhancement of the Ce3+ - related electron recombination luminescence with the increasing temperature in the 10–180 K range. ; ERDF TK141 No. 2014-2020.4.01.15-0011; Ministry of Education, Youth and Sports of the Czech Republic no. LO1409, LM2015088 and CZ.02.1.01/0.0/0.0/16 013/ 0001406; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²