Publications by authors named "Takaki Masaki"

Phosphors with sufficient red emission component are necessary for warm white light-emitting diodes. In this work on (Sr,Ba)2(1-x)Eu2xSiO4 phosphors, (Sr,Ba)1.5Eu0.

View Article and Find Full Text PDF

A novel liquid-phase precursor (LPP) method using precursor nanoparticles (PNs) is proposed to synthesize yttrium aluminum garnet nano-sized phosphor (Y3Al5O12:Ce3+, nano-YAG:Ce) at 1100-1500 degrees C for 5 h. The influences of the heat-treatment and morphology properties of the PNs on the luminescence properties of the nano-YAG:Ce phosphor were investigated. Nano-YAG:Ce phosphor with better morphology and high luminescence efficiency was obtained with heat-treatment of PNs at 1200 degrees C.

View Article and Find Full Text PDF

We report a new dicalcium silicate phosphor, Ca(2-x)Eu(x)SiO4, which emits red light in response to blue-light excitation. When excited at 450 nm, deep-red emission at 650 nm was clearly observed in Ca1.2Eu0.

View Article and Find Full Text PDF

The Ca(1-x)Mg(x)Al12O19:Mn4+ compounds were prepared by liquid phase precursor (LPP) methods for use in white light emitting diodes (LEDs) based on nano red phosphor. The effect of adding Mg element on the relative emission characteristics of Ca(1-x)Mg(x)Al12O19:Mn4+ is discussed in terms of the charge compensation effect. The LPP synthesis, the relative emission intensity of Ca(1-x)Mg(x)Al12O19:Mn4+ containing ratio of 0.

View Article and Find Full Text PDF