LANTHANIDE-DOPED UPCONVERSION NANOCRYSTALS: SYNTHESIS AND OPTICAL PROPERTIES STUDY

Abstract

UPCONVERSION PHOSPHOR MATERIALS ARE ATTRACTING CONSIDERABLE ATTENTION FOR THEIR POTENTIAL APPLICATIONS IN THREE-DIMENSIONAL DISPLAYS TECHNOLOGIES, BIO-IMAGING AND SOLAR CELLS WITH IMPROVED EFFICIENCY. THIS DISSERTATION AIMS TO DEVELOP NOVEL LANTHANIDE-DOPED UPCONVERSION LUMINESCENT NANOMATERIALS. FIRSTLY, THREE MODELS OF CORE-SHELL-SHELL STRUCTURES NANOPARTICLES FOR ENERGY MIGRATION-MEDIATED UPCONVERSION WAS DEMONSTRATED. THE UPCONVERSION EMISSIONS OF EU3+, TB3+, SM3+ AND DY3+ WERE SUCCESSFULLY OBTAINED IN THE ACTIVE SHELL STRUCTURE UNDER 808 NM CW LASER EXCITATION. NEXT, THE ER3+-DOPED NANOCRYSTALS WAS INTRODUCED FOR FINE TUNING OF EMISSION COLOR UNDER 1532 NM CW LASER EXCITATION. BY DELIBERATELY TUNING THE COMPONENT AND CONCENTRATION OF ACTIVATORS, MULTICOLOR UPCONVERSION LUMINESCENCE COULD BE ACHIEVED. FINALLY, A RATIONAL DESIGN AND SYNTHESIS OF HIGHLY STABLE LANTHANIDE-DOPED K2YF5 UPCONVERSION NANOBELTS WERE PRESENTED. AS-PREPARED NANOBELTS EXHIBIT STRONG NEAR-INFRARED TO VISIBLE U