• 한국전기전자재료학회논문지
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• 제11권3호
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• pp.242-247
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• 1998

In this study, we have synthesized $ZnGa_2O_4$:Mn,X powder doped with Mn, MnO, $MnF_2$ and $MnCl_2$, low voltage green emitting phosphor, in vacuum atmosphere. From PL spectra, the intensity of the emission peak, the brightness with coactivator show that $ZnGa_2O_4$:Mn,Cl > $ZnGa_2O_4$:Mn,F > $ZnGa_2O_4$:Mn,O > $ZnGa_2O_4$:Mn. These improvement of the brightness are caused by the increase of the concentration of $Mn^{2+}$ ion. In case of $ZnGa_2O_4$:Mn,Cl and ZnGa$_2$O$_4$:Mn,F, the brightness is enhanced much more, which is owed to the decrease of defect of host material. For $ZnGa_2O_4$:Mn,Cl phosphor fabricated with optimized condition, the decay time becomes short from 30 ms of the $ZnGa_2O_4$:Mn and $ZnGa_2O_4$:Mn,O to 6 ms and the brightness of CL at 1 kV, 1 mA is 60 cd/$m^2$.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.10-16
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• 2010

본 논문에서는 ZnO와 $Ga_2O_3$ 분말을 1 : 1의 mole비로 혼합하고 여기에 Mn을 첨가하여 Ar 주입 상태와 진공 상태에서 조성된 $ZnGa_2O_4$ : Mn을 합성하였다. 제작된 $ZnGa_2O_4$ : Mn의 발광 스펙트럼 관찰을 하여 산소의 성분 변화가 발광 특성에 미치는 영향을 설명하였다. 또한 저온의 Photoluminescence(PL) 스펙트럼으로부터 Mn의 site symmetry가 발광 스펙트럼에 미치는 영향을 설명하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.703-708
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• 2009

본 논문에서는 ZnO와 $Ga_2O_3$ 분말을 1:1의 mole비로 혼합하고 여기에 Mn을 첨가하여 Ar이나 진공 분위기에서 $ZnGa_2O_4$ : Mn을 합성하였다. 제작된 $ZnGa_2O_4$ : Mn의 발광 스펙트럼, 표면 사진 및 성분비를 측정하여 산소의 성분 변화가 발광 특성에 미치는 영향을 규명하고자 하였다. 또한 저온의 Photoluminescence(PL) 스펙트럼으로부터 Mn의 site symmetry가 발광 스펙트럼에 미치는 영향을 설명하였다.

• Transactions on Electrical and Electronic Materials
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• 제4권6호
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• pp.13-16
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• 2003

Mn-doped $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film phosphors have been grown using a pulsed laser deposition technique under various growth conditions. The structural characterization carr~ed out on a series of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) films grown on MgO(l00) substrates usmg Zn-rich ceramic targets. Oxygen pressure was varied from 50 to 200 mTorr and Zn/Ga ratio was the function of oxygen pressure. XRD patterns showed that the lattice constants of the $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film decrease with the substitution of sulfur and selenium for the oxygen in the $ZnGa_2O_4$. Measurements of photoluminescence (PL) properties of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin films have indicated that MgO(100) is one of the most promised substrates for the growth of high quality $ZnGa_2O_{4-x}M_{x}$:$Mn^{2+}$ (M=S, Se) thin films. In particular, the incorporation of Sulfur or Selenium into $ZnGa_2O_4$ lattice could induce a remarkable increase in the intensity of PL. The increasing of green emission intensity was observed with $ZnGa_2O_{3.925}Se_{0.075}:$Mn^{2+}$ and $ZnGa_2O_{3.925}S_{0.05}$:$Mn^{2+}$ films, whose brightness was increased by a factor of 3.1 and 1.4 in comparison with that of $ZnGa_{2}O_{4}$:$Mn^{2+}$ films, respectively. These phosphors may promise for application to the flat panel displays.

• 한국재료학회지
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• 제22권11호
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• pp.575-580
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• 2012

The purpose of this study is to investigate the crystalline structure and optical properties of (GaZn)(NO) powders prepared by solid-state reaction between GaOOH and ZnO mixture under $NH_3$ gas flow. While ammoniation of the GaOOH and ZnO mixture successfully produces the single phase of (GaZn)(NO) solid solution within a GaOOH rich composition of under 50 mol% of ZnO content, this process also produces a powder with coexisting (GaZn)(NO) and ZnO in a ZnO rich composition over 50 mol%. The GaOOH in the starting material was phase-transformed to ${\alpha}$-, ${\beta}-Ga_2O_3$ in the $NH_3$ environment; it was then reacted with ZnO to produce $ZnGa_2O_4$. Finally, the exchange reaction between nitrogen and oxygen atoms at the $ZnGa_2O_4$ powder surface forms a (GaZn)(NO) solid solution. Photoluminescence spectra from the (GaZn)(NO) solid solution consisted of oxygen-related red-emission bands and yellow-, green- and blue-emission bands from the Zn acceptor energy levels in the energy bandgap of the (GaZn)(NO) solid solutions.

• Journal of Ceramic Processing Research
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• 제22권2호
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• pp.169-178
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• 2021

In this work, in-flight synthesis route of Ga doped ZnO (GZO) nano-powders was investigated experimentally and numerically, using Radio-Frequency (RF) induction plasmas. For experimental study, mixture of micron-sized ZnO and Ga₂O₃ powders were treated by RF induction plasmas, then, the as-treated powders were retrieved from reactor bottom and filtration for characterization. For numerical study, single particle model was combined with two-dimensional simulation code of RF induction plasma to predict the particle behaviors of ZnO and Ga₂O₃ depending on their sizes. First, experimental results showed that filtration-retrieved powders were characterized as GZO nano-powders although gallium content can be decreased due to Ga₂O₃ decomposition into sub-oxides at the elevated temperatures. From reactor bottom, however, spherical structures consisting of Ga₂O₃ and ZnO particles were observed in sub-millimeter sizes. Numerical results predicted that micron-sized (≤ 10 ㎛) ZnO and Ga₂O₃ particles can vaporize easily during the flight of plasma, while particles with the sizes of 25~100 um were simulated to be partially evaporated or unevaporated. Comparing these experimental and numerical results indicates that GZO nano-powders can be synthesized from vapor species of ZnO and Ga₂O₃, which are primarily produced by in-flight treatment of micron-sized ZnO and Ga₂O₃ powders in RF induction plasmas.

• 한국전기전자재료학회논문지
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• 제23권1호
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• pp.14-17
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• 2010

$ZnGa_2O_4$ powder were prepared by combustion method and $Mn^{2+}$ ions, a green luminescence activator, and $Cr^{3+}$ ions, a red luminescence activator were separately doped into $ZnGa_2O_4$. The characteristics of the synthesized nano powder were investigated by means of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and photoluminescence (PL). The various $ZnGa_2O_4$ peaks, with the (311) main peak, appeared at all sintering temperature XRD patterns. The PL specctrums of $ZnGa_2O_4$ powder showed main peak of 425 nm, and maximum intensity at the sintering temperature of $1200^{\circ}C$. SEM images shown that nano sized particles(about 200 nm) were of spherical shape. The characteristics of $ZnGa_2O_4$ containing 0.004 mol $Mn^{2+}$(505 nm, green) and $ZnGa_2O_4$ containg 0.002 mol $Cr^{3+}$ (696 nm, red) were shown to be the best.

• 한국재료학회지
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• 제2권5호
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• pp.360-365
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• 1992

Ga 첨가효과 및 Sputter 제조조건이 전기적 특성에 미치는 영향을 고찰하기 위해 ZnO분말과 G$a_2O_3$분말을 소결하여 타겟트를 제조하여 Sputter법으로 유리기판에 Ga-doped ZnO 다결정박막을 제조하였다. RF 전력밀도, 아르곤 개스압력 및 Ga 함유량등을 최적화한 후 제조한 투명한 Ga-doped ZnO 박막의 비저항은 1$0^{-3}$ohm-cm이며, undoped 및 Ga-doped ZnO 박막의 전자농도는 각 $10^{18}$, $10^{21}$/c$m^2$이였다. 공기와 질소분위기에서 열처리를 행하였을 때 Ga-doped ZnO 박막의 비저항은 $10^{2}$ order 증가하였다. 가시광영역의 투과율은 80% 이상이였으며, Ga 함유량이 증가하면 optical band gap도 넓어졌다.

• 한국결정성장학회지
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• 제26권3호
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• pp.109-114
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• 2016

용매열합성법과 하소 과정으로 이루어진 두 단계 공정을 통해 단분산된 마이크로 크기의 구형 $ZnGa_2O_4$ 입자를 합성하였다. 합성된 3차원 구조의 구형 $ZnGa_2O_4$ 입자는 핵 생성과정에서 발생된 $ZnGa_2O_4$ 핵들이 자기 조립에 의해 형성된다. 이렇게 3차원 구조의 입자를 형성하는 원리인 '핵 성성'과 '자기 조립' 과정은 계면활성제인 PEG(polyethylene glycol)의 영향을 받는다. 그 이유는 계면활성제인 PEG의 농도가 임계응집농도(critical aggregation concentration)를 결정짓기 때문이다. 그리고 $ZnGa_2O_4$ 단상 합성을 위해 원료인 zinc acetate의 양을 조절했으며, 최적의 하소 조건을 결정하고자 TG-DTA를 통해 열적 거동을 확인했다. 또한 열처리 전 모체와 $900^{\circ}C$에서 1시간의 열처리 과정을 거친 산화물을 구성하는 작용기의 변화를 규명하기 위해 FT-IR을 측정하였다.

• Transactions on Electrical and Electronic Materials
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• 제12권1호
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• pp.11-15
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• 2011

In this study, $ZnGa_2O_4$ phosphors in its application to field emission displays and electroluminescence were synthesized through the precipitation method and $Mn^{2+}$ ions. A green luminescence activator, $Cr^{3+}$ ions, and a red luminescence activator were separately doped into $ZnGa_2O_4$, which was then screen printed to an indium tin oxide substrate. The thick films of the $ZnGa_2O_4$ were deposited with the various thicknesses using nano-sized powder. The best luminescence characteristics were shown at a thickness of 60 ${\mu}m$. Additionally, green-emission $ZnGa_2O_4:Mn^{2+}$ and red-emission $ZnGa_2O_4:Cr^{3+}$ phosphor thick films, which have superior characteristics, were manufactured through the screen-printing method. These results indicate that $ZnGa_2O_4$ phosphors prepared through the precipitation method have wide application as phosphor of the full color emission.