• 한국재료학회지
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• 제16권1호
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• pp.58-62
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• 2006

Effects of doping concentration and annealing atmosphere on the luminescent properties of $Er^{3+}$ doped ZnO phosphor powders were investigated. Photoluminescence (PL) spectra of ZnO:Er exhibit an orange emission band at around 575 nm, while those of pure ZnO show a green emission at 520 nm. Emission difference between ZnO:Er and pure ZnO is attributed to the energy transfer of Er ions in ZnO. The highest PL intensity is obtained by doping 1 mol% Er to ZnO. Luminescent properties of ZnO:Er phosphors annealed at $N_2$+vacuum atmosphere are superior to those annealed at $N_2$ atmosphere.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1283-1286
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• 2009

The structural and optical properties on $Tb^{3+}$ addition into LiGd$(PO_3)_4$ compound were investigated by X-ray powder diffraction and photoluminescence spectroscopy. The emission spectrum shows the strongest peak corresponding to the $^5D_4{\rightarrow}^7F_5$ transition of $Tb^{3+}$ at 546 nm under 147 nm and 173 nm excitation. 85 mol% concentration of $Tb^{3+}$ for LiGd$(PO_3)_4$ is much higher than other Tb-doped phosphors.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.51-61
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• 2007

This paper concerns about the requirement analysis for night vision imaging system(NVIS), whose purpose is to intensify the available nighttime near infrared(IR) radiation sufficiently to be caught by the human eyes on a miniature green phosphor screen. The requirements for NVIS are NVIS radiance(NR), chromaticity, daylight legibility/readability, etc. The NR is a quantitative measure of night vision goggle (NVG) compatibility of a light source as viewed through goggles. The chromaticity is the quality of a color as determined by its purity and dominant wavelength. The daylight legibility/readability is the degree at which words are readable based on appearance and a measure of an instrument's ability to display incremental changes in its output value. In this paper, the requirements of NR, chromaticity, and daylight legibility/readability for Type I and Class B/C NVIS are analyzed. Also the rationale is shown with respect to those requirements.

• 센서학회지
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• 제6권1호
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• pp.63-71
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• 1997

ZnS:Mn/$ZnS:TbF_{3}$적층구조의 TFEL(thin-film eletroluminescent)소자를 제작하였으며, 이때 절연층으로 (Pb,La)$TiO_{3}$(이하PLT)와 $SiO_{2}$박막을 이용하였다. TFEL소자는 $78V_{rms}$의 문턱전압과 $100V_{rms}$의 인가전압에서 $400{\mu}W/cm^{2}$의 휘도를 나타내었다. TFEL소자의 발광스펙트럼은 450nm에서 630nm사이의 파장대를 보이고 있다. 제작된 TFEL소자는 컬러필터를 병용함으로서, 적 녹 청의 색상을 구현하는 TFEL소자로 활용할 수 있다.

• 한국표면공학회지
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• 제50권3호
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• pp.206-211
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• 2017

$BiNbO_4:RE^{3+}$ (RE = Dy, Eu, Sm, Tb) phosphors were prepared by solid-state reaction at $1100^{\circ}C$ and their structural, photoluminescent, and morphological properties were investigated. XRD patterns exhibited that all the synthesized phosphors exhibited a triclinic system with a dominant (210) diffraction peak, irrespective of the type of activator ions. The surface morphologies of rare-earth-ion-doped $BiNbO_4$ phosphors were found to depend strongly on the type of activator ions. The $Eu^{3+}$ and $Dy^{3+}$ doped $BiNbO_4$ phosphors revealed a strong red (613 nm) emission resulting from the $^5D_0{\rightarrow}^7F_2$ transition of $Eu^{3+}$ and a dominant yellow (575 nm) emission originating from the $^4F_{9/2}{\rightarrow}^6H_{13/2}$ transition of $Dy^{3+}$ respectively, which were the electric dipole transitions, indicating that the activator ions occupy sites of non-inversion symmetry in the $BiNbO_4$ phosphor. The main reddish-orange emission spectra of $Sm^{3+}$-doped $BiNbO_4$ phosphors were due to the $^4G_{5/2}{\rightarrow}^6H_{7/2}$ (607 nm) magnetic dipole transition, indicating that the $Sm^{3+}$ ions were located at inversion symmetry sites in the $BiNbO_4$ host lattice. As for $Tb^{3+}$-doped phosphors, green emission was obtained under excitation at 353 nm and its CIE chromaticity coordinates were (0.274, 0.376). These results suggest that multicolor emission can be achieved by changing the type of activator ions incorporated into the $BiNbO_4$ host crystal.

• 한국결정성장학회지
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• 제17권2호
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• pp.57-62
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• 2007

Metallo-organic decomposition(MOD)법으로 willemite 녹색 형광체를 합성하였고, 열처리 온도($800{\sim}1100^{\circ}C$) 및 Mn 활성제 농도($4{\sim}12 mol%$)에 따른 발광특성과 상합성에 대해 조사하였다. 254nm 여기원을 사용한 측정에서 형광체의 열처리 온도가 $800^{\circ}C$에서 $1000^{\circ}C$로 증가함에 따라 상대 발광 피크강도는 크게 증가하였고, XRD 분석 결과 $1000^{\circ}C$ 이상의 열처리 온도에서 전형적인 willemite 결정 구조를 보여 주었다. $1000^{\circ}C$의 온도로 열처리한 willemite 형광체는 Mn 활성제 농도가 8mol% 일 때 최대 발광 강도를 나타내었으며 10mol% 이상에서는 발광 강도가 급격히 저하되는 농도 ??칭 현상이 관찰되었다. SEM 분석 결과 형광체 입자 형상은 구형에 가까웠으며 $1000^{\circ}C$에서 소성된 형광체 입자 크기는 약 $0.4{\sim}0.5{\mu}m$ 이었다.

• 센서학회지
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• 제15권5호
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• pp.323-327
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• 2006

Manganese, copper and chlorine-doped ZnS phosphors (ZnS:Mn,Cu,Cl) were synthesized through solid-state reaction. Manganese was added in the range of amount $1.4{\sim}5.3$ mol % to ZnS phosphors containing 0.2 or 1.0 mol % of copper and a small amount of chlorine. As-synthesized phosphors showed a spherical morphology with a mean size of ${\sim}20\;{\mu}m$ and structural properties of Wurtzite, which were identified by SEM and XRD, respectively. Optical properties of ZnS:Mn,Cu,Cl synthesized with various concentrations of activators were analysed by both of PL and EL spectra. Samples mainly showing only 580 nm-orange emission by 380 nm-UV excitation gave different EL spectra of blue, green, and orange emissions at 450, 480 and 580 nm, respectively, depending on concentrations of $Cu^{2+}$ and $Mn^{2+}$.

• 한국재료학회지
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• 제8권7호
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• pp.616-620
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• 1998

착체증합법 및 연소합성법에 의해 Zn_{0.994}Mn_{0.006}Ga_2O_4$녹색형광체 분말을 합성하였으며, 이들의 분말 및 발광특성을 XRD, SEM, BET, PL 등을 사용하여 조사하였고, 이를 고상반응법에 의하여 합성한 시료와 비교하였다. 착체중합법과 연소합성법에 의해 합성한 시료는 각각 $500^{\circ}C$와 $400^{\circ}C$에서 단일 스피텔 상이 생성되었으며, 이들의 입자크기는 고상반응에 의해 합성된 분말에 비하여 작았다. 한편, 착체중합법에 의하여 합성한 분말의 발광강도는 열처리 온도가 $900^{\circ}C$일 때, 연소합성법에서는 반응온도가 $400^{\circ}C$일 때 각각 최대값을 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1062-1065
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• 2004

The importance of display is becoming increasingly important due to the development of information and industry where it leads to diverse and abundant information in today's society. The demand and application range for FPD(Flat Panel Display), specifically represented by LCD(Liquid Crystal Display) and PDP(Plasma Display Panel), have been rapidly growing for its outstanding performance and convenience amongst many other forms of display. The current focus has been on OLED(Organic Light Emitting Diode) in the mobile form, which has just entered into mass production amid the different types of FPD. Many studies are being conducted in regards to device, vacuum evaporation, encapsulation, and drive circuits with the development of device as a matter of the utmost concern. This study develops a new type of light-emitting materials by synthesizing medical polymer organic chitosan and phosphor material CuS. Chitosan itself satisfies the Pool-Frenkel Effect, an I-V specific curve, with a thin film under $20{mu}m$, and demonstrates production possibility for a living body sensors solely with the thin film. Furthermore, it enables production possibility for EML of organic EL device(Emitting Layer) with liquid Green light emitting and Blue light emitting as a result of synthesis with phosphor material.

• 전자공학회논문지D
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• 제34D권2호
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• pp.27-37
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• 1997

Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and $Si_3N_4$ powders were used to synthesize $(Mg_xZn_{1-x})SiN_2$ host materials. $Tb_4O_7$ and $Eu_2O_3$ powdrs were added as luminescent centers. Very sharp emission spectra of $Tb^{3+}$ ions were observed from $Mg._5Zn._5SiN_2:Tb$ sampels sintered at $1400^{\circ}C$ for an hour and the maximum intensity of emission spectra occured at wavelength of 550nm (green light). Synthetic conditions of $(Mg_xZn_{1-x})SiN_2:Eu$ phosphors were optimized for the hghest luminescence. The Eu concentrations were varied from 0.2% to 1.6%. Before firing, the powders were mixed using ballmills, methanol, acetone, or D.I. water. The Mg/Zn ratio also were varied from x=0.3 to x=0.7. The maximum PL intensity was obtained from a sample with 1.2% Eu concentration and the powder was mixed with methanol and dried before firing. The maximum intensity of the emission spectra occurred t the wavelength of 470nm(blue light). TFEL devices fabricated by using sputter deposition of $(Mg._3Zn._7)SiN_2:Eu$ phosphor layer showed yellowish white emission at the phosphor field of 2MV/cm.