Dans le cadre du programme CNRS “Ambassadeur de l’INC”, le professeur Kiyoshi SHIMAMURA donnera un séminaire le jeudi 05 décembre 2019 à 10h, dans l’amphithéâtre 1 du Déambulatoire.
Recent activities of our group related with novel single crystals with advantageous characteristics will be reviewed. Briefly, recent trend of bulk single crystals will also be reviewed. A new concept of high-brightness white LEDs based on Ce:YAG single crystal phosphor plates (SCPPs),which can overcome the conventional temperature- and photo- degradation problems, is proposed. SCPPs demonstrated excellent thermal stability with no temperature quenching, high values of luminous efficacy and increased quantum efficiency.
Tb3Sc1.95Lu0.05Al3O12 (TSLAG) single crystals have been designed and grown for high-power laser machinery. They showed a higher visible-UV transparency and a larger Faraday rotation than TGG. They are therefore very promising material in particular for new magneto- optical isolator applications. 2-inch size Ca3TaAl3Si2O14 (CTAS) single crystals for high temperature piezoelectric sensors have been grown. An oxygen-less atmosphere favored a higher electrical resistivity, with three orders of magnitude higher values than that of reference La3Ta0.5Ga5.1Al0.4O14 (LTGA). Ga2O3 and Mg2Si single crystals are also introduced as wide/narrow bandgap semiconductors.