• Korean Journal of Materials Research
• /
• v.29 no.4
• /
• pp.241-251
• /
• 2019

There are several manufacturing techniques for developing thermionic cathodes for vacuum ultraviolet(VUV) ionizers. The triple alkaline earth metal emitters(Ca-Sr-Ba) are formulated as efficient and reliable thermo-electron sources with a great many different compositions for the ionizing devices. We prepare two basic suspensions with different compositions: calcium, strontium and barium. After evaluating the electron-emitting performance for europium, gadolinium, and yttrium-based cathodes mixed with these suspensions, we selected the yttrium for its better performance. Next, another transition metal indium and a lanthanide metal neodymium salt is introduced to two base emitters. These final composite metal emitters are coated on the tungsten filament and then activated to the oxide cathodes by an intentionally programmed calcination process under an ultra-high vacuum(${\sim}10^{-6}torr$). The performance of electron emission of the cathodes is characterized by their anode currents with respect to the addition of each element, In and Nd, and their concentration of cathodes. Compared to both the base cathodes, the electron emission performance of the cathodes containing indium and neodymium decreases. The anode current of the Nd cathode is more markedly degraded than that with In.

• Korean Journal of Materials Research
• /
• v.10 no.3
• /
• pp.204-211
• /
• 2000

The $(Y,Gd)BO_3:Eu$ red phosphors for PDP application were synthesized by ultrasonic spray method and then their photoluminance properties were investigated under 147nm VUV irradiation. The precursor solution of acetates of Y, GD and Eu and boric acid diluted in water was sprayed using 1.7 MHz ultra-sonic sprayer into the reaction tube held at high temperature. The as-sprayed particles were amorphous phase having C-C and C-H bonds due to the insufficient thermal reaction during the pass along the tube. But the sprayed samples followed by heat treatment at $1100^{\circ}C$ had the same crystal structure and chemical composition as those samples followed by solid state reaction. It was found that the $(Y_{0.7}Gd_{0.3})_{0.95} BO_3:Eu_{0.05}^{3+}$ phosphor particles synthesized by spray at $500^{\circ}C$ and then heat treated at $900^{\circ}C$ had a spherical-like shape and fine particle size at $0.7{\mu\textrm{m}}$ having a narrow size distribution, while the phosphor particles made by solid state reaction was $3{\mu\textrm{m}}$ coarse and non-uniform size distribution. The emitting intensity under 147nm VUV excitation for $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}^{3+}$ phosphor prepared by spray method was found to be higher than those phosphor made by solid state reaction and the commercial $(Y,Gd)BO_3:Eu$ product.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2007.11a
• /
• pp.91.1-91.1
• /
• 2007

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.1077-1080
• /
• 2002

Present status of diagnostics and simulations on microplasmas for understandings of the discharge and VUV emission characteristics in a unit cell of plasma display panel is overviewed and their future perspective will be argued towards potential improvement of the characteristics.

• Proceedings of the Optical Society of Korea Conference
• /
• 1996.09a
• /
• pp.5-5
• /
• 1996

• Proceedings of the Korean Society of Potoscience Conference
• /
• 2005.06a
• /
• pp.123-123
• /
• 2005

• Proceedings of the Korean Society of Potoscience Conference
• /
• 2005.06a
• /
• pp.101-102
• /
• 2005

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.522-524
• /
• 2004

The improvement of luminance and luminous efficiency is the one of the most important part in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with binary and ternary gas mixtures of Ne-Xe and He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2$$^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.791-794
• /
• 2003

To synthesize $Gd_{2}O_{3}:Eu$ phosphor powder of nano size and high luminescence efficiency under UV (ultraviolet) and VUV (vacuum ultraviolet) light, organic additives such as citric acid and ethylene glycol and $Na_{2}CO_{3}$ flux were introduced in large-scale spray pyrolysis and critical conditions for forming nano-sized particles were investigated. The $Gd_{2}O_{3}:Eu$ phosphor particles prepared from solutions with organic additives such as citric acid and ethylene glycol had micron size and spherical shape. However, the particles prepared from polymeric precursor solution with $Na_{2}CO_{3}$ flux had nano size and non-aggregation characteristics. The as-prepared spherical particles with micron size turned into nano-sized particles during post-treatment by recrystallization process. The nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles showed higher brightness than the commercial $Y_2O_3:Eu$ phosphor product under both UV light of 254nm and VUV light of 147 nm.

• Proceedings of the KIEE Conference
• /
• 2005.11a
• /
• pp.220-222
• /
• 2005

We can classify two cases in a way to observe an atom of gas state or a molecule using the laser. First case is way to use dispersion phenomenon like Rayleigh scattering, Thomson scattering, Mie scattering, Raman Scattering. And Second case is a way to use change phenomenon like a LAS (Laser Absorption Spectroscopy), LIF (Laser Induced Fluorescent). In this paper, we have measured the meta-stable density and the distribution by using a LAS method in Xe discharge lamp. The laser absorption spectroscopy (LAS) is useful to investigate the behavior of such species. The xenon atoms in the $1S_4$ and $1S_5$ generate excited $Xe^*$(147nm) and $Xe_{2}^*$(173nm) dimers in Xe plasma. It is found that the intensity of VUV 147nm emission is proportional to that of the IR 828nm emission, and the VUV 173nm emission is roughly proportional to that of the IR 823nm emission. The laser is used CW laser that consist of AlGaAs semiconductor and energy level is used 823.16nm wavelength. We measured signal of monochrometer from the lamp center while will change a discharge electric current by 6mA in 3mA and calculated meta-stable state density of a xenon atom through a measured value.