• Electrical & Electronic Materials
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• v.10 no.3
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• pp.262-267
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• 1997

In order to improve the brightness and chromaticity of green emitting low voltage phosphor for FED, we examine PL, PLE and CL emission characteristics of ZnGa$_{2}$O$_{4}$:Mn,O prepared in Ar and vacuum. ZnGa$_{2}$O$_{4}$:Mn,O sintered in vacuum shows about 16 times as bright as the one fabricated in Ar and excellent chromaticity. In PL emission spectra of ZnGa$_{2}$O$_{4}$:Mn,O at low temperature of 9 K, two peaks are observed at 504 nm and 513 nm. At room temperature, the two peaks are superimposed due to the lattice thermal vibrational energy, and only one peak is observed at 509 nm. From PLE measurements, it is believed that the energy levels of the host lattice and Mn ions are coexisted. The energy transfer from the host lattice to the emission center of Mn$^{2+}$ ions occurs.s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.463-465
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• 2005

The $ZnGa_2O_4$:Mn phosphor was synthesized through solid-state reactions at the various molar ratio of Mn from 0.002 % to 0.01 %. Structural and optical properties of the $ZnGa_2O_4$:Mn phosphor was investigated by using X-ray diffraction (XRD), and cathodoluminescence (CL) measurements. The XRD patterns show that the Mn-doped $ZnGa_2O_4$ has a (311) main peak and a spinel phase. Also the emission wavelength shifts from 420 to 510 nm in comparison with $ZnGa_2O_4$ when Mn is doped in $ZnGa_2O_4$. These results indicate that $ZnGa_2O_4$:Mn phosphors hold promise for potential applications in field-emission display devices with high brightness operating in green spectral regions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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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.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.652-656
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• 2003

The green emitting phosphor, BnGa$_2$O$_4$:Mn thin films with spinel structure were deposited by rf magnetron sputtering at various Ar/O$_2$ ratios. Thin film phosphors were heat-treated in air and $N_2$+vacuum atmosphere, respectively. Effects of Ar/O$_2$ ratios and annealing conditions on the structural and photoluminescence (PL) and cathodeluminescence (CL) properties were investigated. Luminous properties were more improved by inhibiting the films from contacting with oxygen during heat treatment.

• Journal of the Korean Ceramic Society
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• v.35 no.6
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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.

• Transactions on Electrical and Electronic Materials
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• v.12 no.1
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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.

• Journal of the Korean institute of surface engineering
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• v.30 no.1
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• pp.57-62
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• 1997

Green-emitting $ZnGa_2O_4$ : Mn phosphors were synthesized by a thermal method and their low-voltage cathodoluminescent characteristics were examined for the field emitter display (FED) application. Low efficiency of $ZnGa_2O_4$ : Mn phosphors could be ascribed to the low penetration depth of into phosphors, which might results in charge accumulation on the phosphors screen. For increasing cathodoluminescent of $ZnGa_2O_4$ : Mn under low voltage excitation, wide band-gap oxide materials were added to the $ZnGa_2O_4$: Mn powder. It is found that the luminance can be increased by 20%. Measurement of leakage current on the phosphor screen shows that the enhancement of low-voltage cathodoluminescent by additive materials is mainly due to the consumption of surface charges on the phosphor.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1517-1519
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• 1999

FED용 형광체로 사용되는 $ZnGa_2O_4$를 Glycine Nitrate Process로 합성하여 고상 반응법으로 합성한 $ZnGa_2O_4$ 분말과 비교 분석하였다. 또한 Glycine Nitrate Process로 제조시 Mn의 doping 농도를 변화시키면서 각각의 조성비에 따른 발광특성을 알아보았다. TGA 측정 결과 GNP법으로 합성된 $ZnGa_2O_4$의 경우약 $300^{\circ}C$이상에서 무게감량이 없으며, XRD 상분석 결과 연소반응 후 이미 상형성이 이루어짐을 알 수 있었다. PL측정을 결과 GP(Glycine Nitrate Process)로 제조된 $ZnGa_2O_4$ 분말의 발광효율이 고상 반응법으로 제조된 분말보다 우수하였으며, 균일하고 비표면적이 큰 단일상임이 관찰되었고, 더 작은 에너지와 시간으로 제조할 수 있는 장점이 있었다.

• Bulletin of the Korean Chemical Society
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• v.18 no.6
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• pp.608-612
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• 1997

The preparation and photoluminescence properties of $ZnGa_2O_4$ : Mn phosphor are presented. Under 254 nm excitation $Zn_1-_xMn_xGa_2O_4$ exhibits the green emission band at 506 nm wavelength and maximum intensity where x=0.005. The manganese activated $ZnGa_2O_4$ phosphor prepared by the polymerized complex method shows a remarkable increase in the emission intensity and is smaller particle size than that prepared by conventional method. Also, electron paramagnetic resonance study on $ZnGa_2O_4$ : Mn powders indicates that the increase in emission intensity after firing treatment in mild hydrogen reducing atmosphere is due to the conversion of the higher valent manganese to $Mn^{2+}$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.432-436
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• 2006

The $ZnGa_2O_4$ and Mn, Cr-doped $ZnGa_2O_4$ Phosphors were synthesized through conventional solid state reactions. The XRD patterns show that the $ZnGa_2O_4$ has a (3 1 1) main peak and a spinel phase. The emission wavelength of $ZnGa_2O_4$ showed main peak of 420 nm and maximum intensity at the sintering temperature of $1100^{\circ}C$. In the crystalline $ZnGa_2O_4$, the Mn shows green emission (510 nm, $^4T_1-^6A_1$) with a quenching concentration of 0.6 mol%, and the Cr shows red emission (705 nm, $^4T_2-^4A_2$) with a quenching concentration of 2 mol%. These results indicate that $ZnGa_2O_4$ Phosphors hold promise for potential applications in field emission display devices with high brightness operating in full color regions.