• 한국세라믹학회지
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• 제51권6호
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• pp.533-538
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• 2014

Today, silicon and epoxy resin are used as materials of conversion lenses for white LEDs on the basis of their good bonding and transparency in LED packages. But these materials give rise to long-term performance problems such as reaction with water, yellowing transition, and shrinkage by heat. These problems are major factors underlying performance deterioration of LEDs. In this study, in order to address these problems, we fabricated a conversion lenses using glass, which has good chemical durability and is stable to heat. The fabricated conversion lenses were applied to a remote phosphor type. In this experiment, the conversion lens for white LED was coated on a glass substrate by a screen printing method using paste. The thickness of the coated conversion lens was controlled during 2 or 3 iterations of coating. The conversion lens fabricated under high heat treatment temperature and with a thin coating showed higher luminance efficiency and CCT closer to white light than fabricated lenses under low heat treatment temperature or a thick coating. The conversion lens with $32{\mu}m$ coating thickness showed the best optical properties: the measured values of the CCT, CRI, and luminance efficiency were 4468 K, 68, and 142.22 lm/w in 20 wt% glass frit, 80 wt% phosphor with sintering at $800^{\circ}C$.

• 한국재료학회지
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• 제24권12호
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• pp.710-714
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• 2014

The effect of titanium dioxide ($TiO_2$) on the properties of color conversion glasses was examined for glasses based on $BaO-ZnO-B_2O_3-SiO_2$. One glass sample, containing 25 mol% of each component, was used as a reference; the other three glass samples contained 1, 3, and 5 mol% $TiO_2$, respectively. The four color conversion glass samples were prepared by sintering a mixture of glass frits and a $YAG:Ce^+$ phosphor. The characteristics of the color conversion glass samples, such as luminous efficacy, luminance, CIE (Commission International de I'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) were analyzed according to the PL spectrum. The refractive index of the glass samples was found to increase with the titanium dioxide content. In conclusion, luminous efficacy of color conversion glasses increased as the content of $TiO_2$ was raised in the glass matrix.

• 한국세라믹학회지
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• 제50권4호
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• pp.280-287
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• 2013

Plate-type phosphor is a promising substitute in overcoming the issues related to the powder phosphor paste mixed with resin. In this research, $Ca-{\alpha}-SiAlON:Eu^{2+}$ plate phosphor ($Ca_xSi_{12-(m+n)}Al_{m+n}O_nN_{16-n}:Eu_y$) was investigated for the varied compositions (m,n) of the host crystal with the fixed Eu content (y). Densification was promoted for the compositions with increasing 'm' values for the m=2n relationship. Dictated by the Eu concentration inside the phosphor crystal, photoluminescence intensity was stronger in ${\alpha}2$ specimen (m = 3.0, n = 1.5) containing the second phases when compared to ${\alpha}1$ specimen (m = 1.5, n = 0.75) comprising a single-phase ${\alpha}$-SiAlON. The concentration of Eu in the non-emitting amorphous interfacial glass phase was 2~4 times of the designed Eu concentration inside the ${\alpha}$-SiAlON crystal.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1199-1202
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• 2005

Inside of working PDP, there exist highly reactive conditions in the gap between two glass panels. MgO film and phosphor have been investigated as a function of discharge, also phosphor and sealing frits have been investigated as a function of temperature. Changes of impurity generation of MgO, phosphor and sealing fits were measured by using x-ray photoelectron spectroscopy (XPS) and quadropole mass spectroscopy (XPS) and quadropole mass spectrometer (QMS). Impurities such as CO, $CO_2$, OH and $H_2O$ were increased during discharge and heating treatment. Gaseous impurities such as carbon compounds and water deteriorated the characteristics of PDP operation during of lifetime. So metal is used to remove the impurities of phosphor and sealing frits during hearting, the result that the quantity of the impurities such as carbon monoxide and water was reduced.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.27-30
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• 2002

Photoconductor for direct detection flat-panel imager present a great materials challenge, since their requirements include high X -ray absorption, ionization and charge collection, low leakage current and large area deposition. Selenium is practical material. But it needs high thickness and high voltage in selenium for high ionization rate. We report comparative studies of detector sensitivity. One is an a-Se with $70{\mu}m$ thickness on glass. The other has hybrid layer of depositting ZnS phosphor with $100{\mu}m$ on a-Se. The leakage current of hybrid is similar to it of a-Se, but photocurrent is lager than a-Se. Both of them have high spatial resolution, but hybrid has higher sensitivity than a-Se at comparable bias voltage.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.795-798
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• 2003

Inside of working PDP, there exist highly reactive conditions in the gap between two glass panels. MgO layer and phosphor have been investigated as a function of discharge and temperature. A drastic reduction in carbon impurity was observed on the surfaces after discharging and heat treatment. Carbon composition on the MgO and phosphor is a dominant factor for their instability

• 접착 및 계면
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• 제17권3호
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• pp.110-116
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• 2016

야간 우천시 수막에 의한 차선의 재귀반사 효율 감소로 운전자의 시인성이 저하되고 있으며 이로 인해 많은 사고가 발생한다. 시인성을 높이기 위해 메틸메타크릴레이트의 현탁중합 시 소수성으로 표면이 개질된 $SrAl_2O_4:Eu^{2+}$,$Dy^{3+}$ 축광 물질을 도입하고 이를 캡슐화하였다. 표면 개질에 사용된 물질과 라디칼 개시제의 종류, 사용된 축광 물질의 양, 그리고 캡슐의 입도가 캡슐 내부의 축광 물질 함량($W_{TGA}$)에 미치는 영향을 TGA를 사용하여 분석하였다. 그 결과 축광 물질의 함량은 7~81 wt%까지 넓은 분포를 나타내었으며, 이러한 결과는 현탁중합이 넓은 함량 범위의 축광 물질을 캡슐화하는데 적합한 것을 의미한다. 축광 물질의 함량이 낮은 경우에는 캡슐의 입도가 감소함에 따라 $W_{TGA}$이 증가하였으나, 축광 물질의 함량이 높을 때에는 캡슐의 입도에 별 영향을 받지 않았다. 축광 캡슐 중 지름 $425{\sim}710{\mu}m$의 축광 캡슐을 활용하여 형광 차선 시편을 제작하였으며 LED램프를 20 min 동안 조사한 후 광원을 제거하였을 때, 100 s 동안 약 $300mcd/m^2$ 이상의 휘도를 유지했다. 이러한 결과로 미루어 보아 제조된 축광 캡슐은 차선 위의 유리 비드를 대체하기에 충분한 가능성을 가짐을 알 수 있었다.

• 한국세라믹학회지
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• 제35권6호
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• pp.619-625
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• 1998

Mn doped {{{{ {Zn {Ga }_{2 }O }_{4 } }} thin film phosphors were prepared on Si(100) wafers and ITO coated glass substrates by rf magnetron sputtering technique and the effects of the substrates dopant and the sputtering paramet-ers were analyzed, Changes of the oreintation were observed after annealine tratment. The grain size of {{{{ {Zn {Ga }_{2 }O }_{4 } }} : Mn thin film deposited on Si wafer was smaller than that on ITO/glass substrate which resulted in higher PL intensity. The PL spectra of Mn doped {{{{ {Zn {Ga }_{2 }O }_{4 } }} thin films showed sharp green luminescence spec-trum. According to CL spectrum it could be concluded that Mn ions acted as an actuator for green emission by substituting Zn atom sites.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.79-84
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• 1999

the photolithographic patterning on an indium-tin oxide (ITO) glass and the electro-phoretic deposition were combined for preparing the screen of the full-color field emission display(FED). the patterns with a pixel of 400$\mu\textrm{m}$ on the ITO-glass were made by etching the ITO with well-prepared etchant consisting of HCL, H2O, and HNO3. Electrophoretic method was carried out in order to deposit each spherical red (R), green(G), and blue (B) phosphor on the patterned ITO-glass. The process parameters such as bias voltage, salt concentration, and deposition time were optimized to achieve clear boundaries. It was found that the etching process of ITO combined with electrophoretic method was cost-effective, provided distinct pattern, and even reduced process steps compared with conventional processes. The application of reverse bias to the dormant electrodes while depositing the phosphors on the stripe pattern was found to be very critical for preventing the cross-contamination of each phosphor in a pixel.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.495-498
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• 2004

PDP use the mixture of inert gases to generate a discharge inside display pixels. Inside of PDP, there exist highly reactive conditions in the gap between two glass panels. MgO layer and phosphor have been investigated as a function of discharge and thermal process. Impurities such as CO, $CO_2$, OH and $H_2O$ in discharge region may deteriorate the characteristics of PDP operation during life time. Change of impurity generation of various MgO and phosphor surfaces were measured by using x-ray photoelectron spectroscopy(XPS) and quadropole mass spectrometer (QMS). Carbon containing species such as C, CO and $CO_2$ were drastically increased on the surfaces during discharge and thermal treatment. Carbon impurities on the MgO and phosphor are the dominant factor for their instability.