title: Influence of vacuum upon preparation and luminescence of Si4+ and Ti4+ codoped Gd2O2S:Eu phosphor.
abstract: As a novel red long afterglow phosphor, Si(4+) and Ti(4+) ion codoped Gd2O2S:Eu phosphor with spherical morphology, sub-micrometer size and narrow particle size distribution was synthesized by solid-state reaction in vacuum. The vacuum synthesis mechanism was determined by thermal analysis. The crystal structure, luminescence properties and mechanisms were investigated respectively by XRD, SEM and fluorescence spectrophotometer. The results show that well-crystallized Gd2O2S:Eu,Si,Ti phosphors are of hexagonal structure which is in agreement with the standard powder peak positions of Gd2O2S hexagonal phase. It displays pure red emission because of the strongest peaks at 627nm and 617nm which are attributed to energy transfer ((5)D0-(7)F2). There is a little blue shift of charge transfer excitation band in the excitation spectra between the bulk and sub-micrometer-sized samples, which may stem from size dependent shift and different lattice distortion in the position of the Eu(3+)-ligand electron transfer absorption/excitation band. To further study the influence of the impurities in Gd2O2S:Eu crystals on crystal growth, the simulated crystal face and its XRD patterns were illustrated. The preferred orientation of crystal growth changed from crystal face (101) to (100) thus to result in different luminescence mechanisms.
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China. Electronic address: fayerswing@hotmail.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yang
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China.
authors.forename: Dachun
authors.initials: D
authors.lastname: Liu
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Ma
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China.
authors.forename: Xiumin
authors.initials: X
authors.lastname: Chen
authors.affiliation: National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, People's Republic of China; Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming,Yunnan 650093, People's Republic of China; State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province, Kunming,Yunnan 650093, People's Republic of China.
authors.forename: Yongnian
authors.initials: Y
authors.lastname: Dai
mesh_terms: D002412:Cations / Q000737:chemistry; D003460:Crystallization; D005063:Europium / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008958:Models, Molecular; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014618:Vacuum
chemical_list: D002412:Cations; D049408:Luminescent Agents; C021197:gadolinium sulfoxylate; D005063:Europium; D005682:Gadolinium; D014025:Titanium; D012825:Silicon
keywords: DFT calculation; Ion doping; Luminescence; Rare earth oxysulfide; Vacuum