Investigation On Ag And Rare Earth Ions Co-Doped Oxyfluoride White Glasses

White light-emitting diode (LED), which is so called the next general lighting, is a topic of increasing interest due to their high luminous efficiency, low power consumption, environment friendly reliability, long life, and so on. In addition, the studies about rare earth ions doped transparent oxyfluoride glass for white LED have aroused scientists’ interest, because it posses some obvious advantages, such as homogeneous light-emitting, better thermal stability, lower production cost and epoxy resin free in assembly process. The use of noble metals to improve of rare earth luminescence has received considerable attention because of their prospective utility in light function glass. Herein, Glasses containing Ag species and rare earth ions (Eu3+, Dy3+, Sm3+, Tb3+) are prepared by melt-quenching technique and the Luminescent properties of the glasses are invertigated.The main contents are listed as follows:1. Ag-Eu3+co-doped oxyfluoride white glasses:Silicate glass:Samples with composition of40SiO2,25Al2O3,19Na2CO3and15LaF3(in mol%) were prepared. The type of luminescent species, the origin of white emission and the enhancement mechanism for red and blue emissions were investigated by means of absorption, emission and excitation spectra, decay lifetime measurements, as well as time-resolved spectroscopy. Results prove that white emission (CIE:X=0.323, Y=0.320) is originated from f-f transitions of Eu3+(red), ML-Ag (very small molecule-like, non-plasmonic Ag particles, green) and5d-4f transition of Eu2+(blue). Our researches show that Ag-Eu co-doped glasses may provide a new platform to design and fabricate novel phosphors for ultraviolet LED chips.Borate glass:Luminescent properties of Ag-Eu3+co-doped80H3BO3-20BaF2glasses prepared by melt-quenching technique at relatively low temperature (1000℃) were characterized by absorption, excitation and emission spectra, and lifetime measurements systematically. A perfect white emission (X=0.373, Y=0.334) has emerged by combined with red, green and blue emissions that originated from Eu3+, very small molecule-like, non-plamonic Ag particles (ML-Ag particles) and single Ag ions, respectively. Under non-resonant excitation (310-370nm), Eu3+emission was enhanced significantly by60times. Our results suggest that Ag-Eu3+co-doped H3BO3-BaF2glasses could be potentially applied as white phosphors in White LED.2. Ag-RE (Dy3+, Sm3+, Tb3+) co-doped oxyfluoride white glasses:Glasses containing Ag species and rare earth ions (Dy3+, Sm3+, Tb3+) were prepared. The type of luminescent species of novel excitation band (230-300nm peaked at255nm) and emission band (300-600nm peaked at350nm) were investigated by absorption, excitation, emission spectra, as well as decay lifetime measurements and can be ascribed to isolated Ag+ions. Owing to energy transfer from Ag+to RE ions, significant enhancements of RE ions emission (76times for Sm3+,41times for Dy3+) were observed for non-resonant UV excitation (255nm). Our research may extend the understanding of interactions between RE ions and Ag species. By combing blue emission of Ag+(300-400nm), green emission of Tb3+(543nm) and red emission of Sm3+(601nm), white emission can be also achieved.