Ha-Kyun Jung

Preparation and characterization of ZnGa2O4:Mn phosphors by multistage precipitation method

The preparation and luminescent properties of ZnGa{sub 2}O{sub 4}:Mn phosphors were investigated. A new multistage precipitation method, denoted as the chemical synthesis method, was developed for preparing Mn-doped ZnGa{sub 2}O{sub 4}. This method features a low temperature formation of phosphors with rod-type shape. The emission intensity of the phosphor prepared by the chemical synthesis method is stronger, by a factor of 3, than that of the phosphor prepared by the conventional method. The electron paramagnetic resonance study of ZnGa{sub 2}O{sub 4}:Mn indicated that the increase in emission intensity of the phosphor obtained by the chemical synthesis method might be due to a homogeneous distribution of Mn{sup 2+} ions in the host lattice.

Effect of the Crystalline Phase of Al 2 O 3 Nanoparticle on the Luminescence Properties of YAGG:Ce 3+ Phosphor under Vacuum UV Excitation

-doped yttrium aluminum gallium garnet (YAGG:), which is a green-emitting phosphor, was synthesized by solid state reaction using -phase or -phase of nano-sized as the Al source. The processing conditions and the chemical composition of phosphor for the maximum emission intensity were optimized on the basis of emission intensity under vacuum UV excitation. The optimum heating temperature for phosphor preparation was . Photoluminescence properties of the synthesized phosphor were investigated in detail. From the excitation and emission spectra, it was confirmed that the YAGG: phosphors effectively absorb the vacuum UV of 120-200 nm and emit green light positioned around 530 nm. The crystalline phase of the alumina nanoparticles affected the particle size and the luminescence property of the synthesized phosphors. Nano-sized was more effective for the achievement of higher emission intensity than was nano-sized . This discrepancy is considered to be because the diffusion of into lattice is dependent on the crystalline phase of , which affects the phase transformation of YAGG: phosphors. The optimum chemical composition, having the maximum emission intensity, was prepared with . On the other hand, the decay time of the YAGG: phosphors, irrespective of the crystalline phase of the nano-sized alumina source, was below 1 ms due to the allowed transition of the activator.

Preparation of Ba 2 Mg(PO 4 ) 2 :Eu Phosphors and Their Photoluminescence Properties Under UV Excitation

【For possible applications as luminescent materials for white-light emission using UV-LEDs,

Preparation and Properties of Spherical BaMgAl 10 O 17 :Eu Phosphor by Multi-step Precipitation Method

Ba_2Mg(PO_4)_2:Eu^{2+}

Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles

phosphors were prepared by a solid state reaction. The photoluminescence properties of the phosphor were investigated under ultraviolet ray (UV) excitation. The prepared phosphor powders were characterized to from a single phase of a monoclinic crystalline structure by a powder X-ray diffraction analysis. In the photoluminescence spectra, the

Photoluminescence properties of Eu2+ and Mn2+-activated BaMgP2O7 as a potential red phosphor for white-emission

Ba_2Mg(PO_4)_2:Eu^{2+}

Luminescent properties of Eu2+-activated (Ba, Sr)3MgSi2O8 phosphor under VUV irradiation

phosphor showed an intense emission band centered at the 584 nm wavelength due to the f-d transition of the

Optical properties of organic/inorganic nanocomposite sol-gel films containing LaPO4:Er,Yb nanocrystals

Eu^{2+}

BaLa

activator. The optimum concentration of

_2

Eu^{2+}