In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. Despite the development of technology for fast screen signal processing, it is very difficult to compose a high-quality screen due to the limitation of blinking driving due to the long afterglow time of the backlight. As the Single-LVDS signal system evolves from the Quad Signal Package to respond to 3D, the problem of processing faster signals within a set time is occurring. is becoming In this study, the aim was to realize this operation within 1 frame time by using the blinking backlight, and the existing cold cathode tube lamp was used as the light source. In general, cold cathode tube lamps have a long afterglow time of green, which is responsible for the main emission wavelength, so it is difficult to realize the above characteristics. A backlight capable of flickering within the time frame of the video frame was manufactured, and by using it, it was possible to confirm the effect of resolving the afterimage in a moving image by leaps and bounds.

Lu3Al5-xGaxO12:Ce3+,Cr3+ powders are prepared using a solid-state reaction method. To determine the crystal structure, Rietveld refinement is performed. The results indicate that Ga3+ ions preferentially occupied tetrahedral rather than octahedral sites. The lattice constant linearly increases, obeying Vegard’s law, despite the strong preference of Ga3+ for the tetrahedral sites. Increasing x led to a blue-shift of the Ce3+ emission band in the green region and a change in the emission intensity. Persistent luminescence is observed from the powders prepared with x = 2–3, occurring through a trapping and detrapping process between Ce3+ and Cr3+ ions. The longest persistent luminescence is achieved for x = 2; its lifetime is at least 30 min. The findings are explained using crystal structure refinement, crystal field splitting, optical band gap, and electron trapping mechanism.

A SrAl2O4:Eu2+,Dy3+ phosphor powder with stuffed tridymite structure was synthesized by glycine-nitratecombustion method. The luminescence, formation process and microstructure of the phosphor powder were investigated bymeans of X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). The XRDpatterns show that the as-synthesized SrAl2O4:Eu2+,Dy3+ phosphor was an amorphous phase. However, a crystalline SrAl2O4phase was formed by calcining at 1200oC for 4h. From the SEM analysis, also, it was found that the as-synthesizedSrAl2O4:Eu2+,Dy3+ phosphor was in irregular porous particles of about 50µm, while the calcined phosphor was aggregated inspherical particles with radius of about 0.5µm. The emission spectrum of as-synthesized SrAl2O4:Eu2+,Dy3+ phosphor did notappear, due to the amorphous phase. However, the emission spectrum of the calcined phosphor was observed at 520nm(2.384eV); it showed green emission peaking, in the range of 450~650nm. The excitation spectrum of the SrAl2O4:Eu2+,Dy3+phosphor exhibits a maximum peak intensity at 360nm (3.44eV) in the range of 250~480nm. After the removal of the pulseXe-lamp excitation (360nm), also, the decay time for the emission spectrum was very slow, which shows the excellent long-phosphorescent property of the phosphor, although the decay time decreased exponentially.

Both photoluminescence and thermal characteristics for SrAl2O4:Eu+2,Dy+3 phosphors synthesizedwith various aluminum compounds (α-Al2O3, γ-Al2O3, amorphous-Al2O3 and Al(OH)3) were investigated in thisstudy. The formation temperature of the host SrAl2O4 crystal is changed by these various aluminumcompounds, as a result of the different thermal decomposition temperature of SrCO3 phase. Among thesecompounds, the amorphous-Al2O3 phase shows the lowest formation temperature of the host SrAl2O4 crystal.The PL emission and excitation spectra of SrAl2O4:Eu+2, Dy+3 phosphor are not affected by these aluminumcompounds. After the removal of the Xenon lamp excitation (360nm), however, the excellent long-phosphorescent property of the phosphor is obtained by the amorphous-Al2O3 phase, although the decay timefor all phosphors decrease exponentially.

In recent days, the study of a new phosphorescent phosphor has been performed in order to overcome the defect of sulfide phosphor and increase the brightness and long after-glow characteristic of phosphorescent phosphor. Particularly, sulfide phosphor usually used is so chemically unstable that the study of oxide phosphors are processing. Eu2+, Nd3+ doped Ba-Al-O phosphors sintered at 600~1500℃ for 2hours had the PL emission spectrum and after-glow over 1200℃. In this system, as the mole concentration of alumina increases, emission bands of phosphors moved from 500nm to 380nm. The optimum concentration of flux was 5wt% and after-glow characteristics of phosphors were found at the host material molar ratio (BaCO3:Al2O3), 1:1 and 1:3.

SrAI2O4:Eu2+를 합성하여 장잔광 축광재료로서 가장 중요한 발광특성과 장잔광특성을 조사하였다. 융제로서 B2O3를 3wt% 첨가한 SrCO3, Eu2O3, AI2O34의 혼합분말은 1000˚C이상에서 모체결정인 SrAl2O4의 단일상이 형성되었으나, 장잔관 형광체로서 최적의 합성조건은 1300˚C, 3시간이었다. 그리고 SrAI2O4:Eu2+는 부활제인 Eu2+의 4f65d1 →4f7천이에 기인하여 황록색발광영역의 520nm(2.384eV)를 최대 발파장으로 하는 450~650nm의 폭넓은 발광스펙트럼을 보였으며, 또한 발광파장을 520nm로 고정하여 측정한 여기스펙트럼의 최대 흡수피크는 360nm이고 250nm에서 480nm의 넓은 범위에서 흡수스펙트럼이 관찰되었다.