• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.539-542
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• 2004

The $ZnGa_2O_4$ phosphor target is synthesized through solid-state reactions at the calcine temperature of $700^{\circ}C$ and sintering temperature of $1300^{\circ}C$ in order to deposit $ZnGa_2O_4$ phosphor thin film by rf magnetron sputtering system. The $ZnGa_2O_4$ phosphor thin film is deposited on Si(100) substrate and prepared $ZnGa_2O_4$ phosphor thin film is annealed by rapid thermal processor(RTP) at $700^{\circ}C$, 15sec. The x-ray diffraction patterns of $ZnGa_2O_4$ phosphor target and thin film show the position of (311) main peak. The cathodoluminescenre(CL) spectrums of $ZnGa_2O_4$ phosphor thin film show main peak of 420nm and maximum intensity at the substrate temperature of $500^{\circ}C$ and annealing temperature of $700^{\circ}C$ 15sec.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.759-762
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• 2001

Mg$_2$SnO$_4$having an inverse spinel structure was selected as a new host material of $Mn^{2+}$ activator. The luminescence of the $Mg_2$SnO$_4$:Mn phosphor prepared by the solid-state reaction were investigated under ultraviolet and low-voltage electron excitation. The Mn-doped magnesium tin oxide exhibited strong green emission with the spectrum centered at 500nm wavelength. It was explained that the green emission in $Mg_2$SnO$_4$:Mn phosphor is due to energy transfer from $^4T_1to ^6A_1\;of\; Mn^{2+}$ ion at tetrahedral site in the spinel structure. The optimum concentration of $Mn^{2+}$/ion exhibiting maximum emission intensity by the low-voltage electron excitation was 0.6mol%. ？

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.8
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• pp.646-651
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• 1998

In this present study, the luminescence characteristics and mechanism of energy $CaTiO_3$:Pr phosphor were studied using disk specimens sintered at various temperatures and envirenment. A single-phase $CaTiO_3$:Pr was synthesized by sintering above 140$0^{\circ}C$ and its crystal structure was found to be perovskite orthorhombic. A dominant peak around 360 nm and a broad peak around 395 nm were observed in the PLE(Photoluminescence Excitation) spectrum of $CaTiO_3$:Pr with fixed emission wavelength at 612 nm, the decay time of 360 nm excitation was found to be longer than that of 395 nm excitation. From this result, it is assumed that the free carrier excited to 360 nm is transferred to 395 nm energy level. Therefore, the decrease in 395 nm intensity observed in CaTiO$_3$:Pr specimens sintered in Ar gas environment induced shorter decay time and improved CL luminescence.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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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.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.240-244
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• 2002

The GdOBr:Ce phosphor were prepared by solid state reaction using starting chemicals of $Gd_2O_3,\;CeO_2\;and\;NH_4Br$. Under 370nm UV excitation, GdOBr:Ce phosphors showed blue emission band with a spectral range of 410∼430nm. The maximum photoluminescence(PL) emission intensity was observed at 2mol% Ce content. In order to look for feasibility of application for low voltage filed emission display, cathodoluminescence(CL) of GdOBr:Ce phosphors were measured. CL emission spectra was found to be in the range of 410∼430nm, which is the same as PL spectra. The phosphors with 1mol% Ce concentration showed the maximum CL emission intensity. For the comparison of degradation property of the prepared phosphors with commercial ones, the electron beam was applied for 10min. From the result, GdOBr:Ce could be used as a blue phosphor for FED.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.601-606
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• 1998

The $SrTi0_3$:Al, Pr red phosphors were prepared by solid state reaction method. Phosphor preparation parameters such as sintering temperature and time were optimized for the photoluminescence(PU intensity and the cathodoluminescence(CL) intensity. Powder samples showed the characteristic X-ray diffraction patterns of the perovskite structure and the average particle size of 3~5/$\mu\textrm{m}$ for particle size distribution(PSD) analysis. Also, scanning electron microscopy for the powder samples showed that the particles are reasonably crystallized with spherical shape. Especially, higher low voltage CL properties of $SrTi0_3$:Al, Pr phosphors than commercial $Y_2O_3$:Eu phosphors are expected to be applied for a low voltage field emission display(FED).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.1013-1016
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• 2005

ZnO nanostructure was fabricated by catalyst-free method using Zn powder in air. The growth temperature was controlled from 450$^{\circ}$C to 600$^{\circ}$C, and the structural and optical properties were investigated by scanning electron microscopy (SEM), photoluminescence (PL), energy dispersive X-ray spectroscopy (EDX) and cathodoluminescence (CL). From all samples both ZnO tetrapods and clusters were observed. No significant dispersion was observed from the ZnO tetrapods, however, ZnO clusters show considerable change in density and size. From the EDX results, atomic composition difference was found. The clusters have O-deficiencies, while tetrapods have stoichiometric composition. Strong luminescence was observed at room temperature. From room temperature PL, UV emission at 380 nm and green emission at 500 nm were observed, and the intensity ratio ($I_{uv}/I_{green}$) increased as growth temperature increases. CL measurements show that the UV emission is closely related with tetrapods and the green emission is dominated from the clusters.