• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.536-539
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• 2004

A novel ink-jet printing method was investigated for fine patterning of phosphor layer in PDP using a precision nozzle printing. A reverse emulsion method was developed for the synthesis of nano-sized phosphor powder that could be formulated in the phosphor ink. The composition of the phosphor ink including charge controlling agents, solvent, dispersant and nano-sized phosphor powder was optimized for the fine patterning of phosphor layer for high resolution PDP.

• 한국재료학회지
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• 제12권10호
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• pp.771-775
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• 2002

$Gd_2$$O_3$:Eu phosphor particles with nano-sized and non-aggregation characteristics were prepared by spray pyrolysis using the spray solution containing polymeric precursor and $Li_2$$CO_3$ flux material. Nano-sized $Gd_2$$O_3$:Eu phosphor particles had higher brightness than the commercial $Y_2$$O_3$:Eu phosphor particles. The $Gd_2$$O_3$:Eu phosphor particles had nano-size and non-aggregation characteristics after heat-treatment at $1000^{\circ}C$ when the addition amount of $Li_2$$CO_3$ flux was 1 wt.% and 3 wt.%. The mean size of particles were 200 nm and 400 nm when the amount of flux was 1 wt.% and 3 wt.%, respectively. The prepared phosphor particles had higher photoluminescence intensity than that of the commercial product regardless of the content of$ Li_2$$CO_3$ flux and had the maximum brightness when the content of flux was 5 wt %. The photoluminescence intensity of the nano-sized $Gd_2$$O_3$:Eu phosphor particles containing 3 wt.% $Li_2$$CO_3$ flux was 125% in comparison with that of the micron-sized $Y_2$$O_3$:Eu commercial product.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.791-794
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• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.383-384
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• 2007

The nano and micro-sized $ZnGa_2O_4$ phosphor were prepared by precipitation method and solid-state method. The luminescence, formation process and structure of phosphor powders were investigated by means of XRD, SEM and PL. The result of XRD analysis showed that $ZnGa_2O_4$ spinel structure was formed at as-prepared in the case of precipitation method. However, micro-sized phosphor was required high heating treatment to have a satisfactory spinel structure. The CL intensity of nano-sized phosphor was about 4-fold higher than that of micro-sized phosphor. The emission spectra of all $ZnGa_2O_4$ phosphor show a self activated blue emission band at around 420 nm in the wide range of 300~600 nm.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1621-1624
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• 2008

Transparent ac-PDP test panel was prepared via a combination of materials including ITO sustaining electrodes, thin film dielectric layer and nano-sized phosphor powders. The thin film dielectric layer was prepared by E-beam evaporation process and phosphor layer was deposited on metal mesh pattern by electrophoretic deposition process. The optical transmittance and luminance of the panel indicated that full color transparent ac-PDP is feasible with the approach.

• Korean Chemical Engineering Research
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• 제43권1호
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• pp.80-84
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• 2005

초음파 분무 열분해 공정에 의해 나노 크기의 $Y_2O_3:Eu$ 형광체 분말들을 합성하였다. 고분자 전구체와 융제로 사용되어진 리튬 탄산염이 나노 크기의 $Y_2O_3:Eu$ 형광체의 형태 및 발광 특성에 미치는 영향에 대해 조사하였다. 고분자 전구체와 융제를 동시에 사용했을 때 분무 열분해 공정에 의해 제조된 구형의 마이크론 크기의 분말들은 고온의 후열처리 과정에서 나노 크기의 분말로 전환되었다. $Y_2O_3:Eu$ 형광체의 평균 크기는 분무용액에 첨가되어지는 고분자 전구체와 융제인 리튬 탄산염의 첨가량 및 분무 열분해 공정의 반응기 온도에 많은 영향을 받았다. 고농도의 고분자 전구체를 함유한 분무용액으로부터 고온의 반응기에서 합성되고, $1,000^{\circ}C$ 이상에서 후열처리한 나노크기 $Y_2O_3:Eu$ 분말들은 진공자외선 하에서 좋은 발광 특성을 나타내었으며, 고상 공정에 의해 합성된 상용의 $Y_2O_3:Eu$ 형광체와 비슷한 발광 세기를 가졌다.

• 한국재료학회지
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• 제22권4호
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• pp.195-201
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• 2012

$Ce^{3+}$-doped yttrium aluminum gallium garnet (YAGG:$Ce^{3+}$), which is a green-emitting phosphor, was synthesized by solid state reaction using ${\alpha}$-phase or ${\gamma}$-phase of nano-sized $Al_2O_3$ 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 $1550^{\circ}C$. Photoluminescence properties of the synthesized phosphor were investigated in detail. From the excitation and emission spectra, it was confirmed that the YAGG:$Ce^{3+}$ 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 ${\gamma}-Al_2O_3$ was more effective for the achievement of higher emission intensity than was nano-sized ${\alpha}-Al_2O_3$. This discrepancy is considered to be because the diffusion of $Al^{3+}$ into $Y_2O_3$ lattice is dependent on the crystalline phase of $Al_2O_3$, which affects the phase transformation of YAGG:$Ce^{3+}$ phosphors. The optimum chemical composition, having the maximum emission intensity, was $(Y_{2.98}Ce_{0.02})(Al_{2.8}Ga_{1.8})O_{11.4}$ prepared with ${\gamma}-Al_2O_3$. On the other hand, the decay time of the YAGG:$Ce^{3+}$ phosphors, irrespective of the crystalline phase of the nano-sized alumina source, was below 1 ms due to the allowed $5d{\rightarrow}4f$ transition of the $Ce^{3+}$ activator.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.386-386
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• 2012

For white light emitting diode (LED) applications, it has been reported that Y3Al5O12:Ce3+ (YAG:Ce) in nano-sized phosphor performs better than it does in micro-sized particles. This is because nano-sized YAG:Ce can reduce internal light scattering when coated onto a blue LED surface. Recently, there have been many reports on the synthesis of nano-sized YAG particles using bottom-up method, such as co-precipitation method, sol-gel process, hydrothermal method, solvothermal method, and glycothermal method. However, there has been no report using top-down method. Top-down method has advantages than bottom-up method, such as large scale production and easy control of doping concentration and particle size. Therefore, in this study, nano-sized YAG:Ce phosphors were synthesized by a high energy beads milling process with varying beads size, milling time and milling steps. The beads milling process was performed by Laboratory Mill MINICER with ZrO2 beads. The phase identity and morphology of nano-sized YAG:Ce were characterized by X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (FESEM), respectively. By controlling beads size, milling time and milling steps, we synthesized a size-tunable and uniform nano-sized YAG:Ce phosphors which average diameters were 100, 85 and 40 nm, respectively. After milling, there was no impurity and all of the peaks were in good agreement with YAG (JCPDS No. 33-0040). Luminescence and quantum efficiency (QE) of nano-sized YAG:Ce phosphors were measured by fluorescence spectrometer and QE measuring instrument, respectively. The synthesized YAG:Ce absorbed light efficiently in the visible region of 400-500 nm, and showed single broadband emission peaked at 550 nm with 50% of QE. As a result, by considering above results, high energy beads milling process could be a facile and reproducible synthesis method for nano-sized YAG:Ce phosphors.

• 공업화학
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• 제19권1호
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• pp.27-30
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• 2008

나노 형광체 합성에 있어서 입자 형상 및 입자 크기의 변화를 알아보기 위해 액상법으로 진행하였으며, 이를 바탕으로 최종적으로 약 80 nm급의 적색 나노 형광체의 합성이 가능하였다. 합성된 두 가지의 $Y_2O_3:Eu^{3+}$와 $YBO_3:Eu^{3+}$ 적색 나노 분말의 특성 평가를 비교하였으며, 그 결과 붕산염을 사용한 $YBO_3:Eu^{3+}$ 형광체 분말이 형상 면에서 약간의 응집이 발생하였으며, PL 특성 면에서도 $Y_2O_3:Eu^{3+}$ 대비 낮은 형광성을 보여주었다.

• 공업화학
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• 제20권5호
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• pp.565-569
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• 2009

녹색과 청색의 나노 형광체 합성에 있어서 입자 형상 및 입자 크기의 변화를 알아보기 위해 액상법으로 진행하였으며, 이를 바탕으로 최종적으로 녹색 형광체의 경우 약 80 nm를, 그리고 청색 형광체의 경우 약 60 nm급의 나노 형광체 분말 합성이 가능하였다. 합성된 두 가지의 $Zn_2SiO_4$ : Mn 녹색 형광체와 BAM : Eu의 청색 나노 형광체 분말의 특성 평가를 비교하였으며, 그 결과 PL 특성면에서 녹색 형광체인 $Zn_2SiO_4$ : Mn이 BAM : Eu의 청색 형광체 대비 높은 형광성을 보여주었다.