Sm³⁺ 도핑된 GdVO₄ 형광체의 제조와 발광 특성

조신호,조선욱,Cho, Shin-Ho,Cho, Seon-Woog 한국진공학회 2012 Applied Science and Convergence Technology Vol.21 No.2

고상 반응법을 사용하여 $Sm^{3+}$ 이온의 함량비를 변화시키면서 $Gd_{1-x}VO_4:{Eu_x}^{3+}$ 형광체 분말을 합성하였다. 모든 형광체 시료의 결정 구조는 $24.76^{\circ}$에 중심을 갖는 (200) 주 회절 피크로 구성되는 정방정계이었으며, 결정 입자의 형상은 $Sm^{3+}$ 이온의 함량비가 0.05 mol일 때 구형에 근접하고 균일한 크기 분포를 나타내었다. 발광 특성의 경우에, $Sm^{3+}$ 이온의 함량비에 관계없이 모든 형광체 분말은 파장 565, 603, 645 nm에 피크를 갖는 각각 황색, 주황색, 적색 형광을 보였다. $Sm^{3+}$ 이온의 함량비가 증가함에 따라 흡수 스펙트럼의 세기는 감소하는 경향을 나타내었으며, $Sm^{3+}$ 이온의 함량비가 0.05 mol일 때 최대 흡수와 발광 스펙트럼이 관측되었고, 대칭비의 값은 1.19이었다. $Gd_{1-x}VO_4:{Eu_x}^{3+}$ phosphor powders were synthesized with changing the concentration of $Sm^{3+}$ ion by using a solid-state reaction method. The crystal structures of all the phosphors were found to be a tetragonal system, composed of (200) diffraction peak centered at $24.76^{\circ}$, and the morphology of grains approached the spherical form with homeogenous size distribution when the concentration of $Sm^{3+}$ ion was 0.05 mol. As for the photoluminescence properties, all of the phosphor powders, irrespective of $Sm^{3+}$ ion concentration, indicated the yellow, orange, and red emission peaked at 565, 603, and 645 nm respectively. As the concentration of $Sm^{3+}$ ion increases, the intensity of excitation spectrum showed a decreasing tendency on the increase of Sm3+ ion concentration. The maximum excitation and emission spectra were observed and the symmetry ratio was 1.19 at 0.05 mol of $Sm^{3+}$ ion.

Eu³⁺ 농도에 따른 적색 형광체 Gd_1-xVO₄:Eu_x³⁺의 형광 특성

조신호,조선욱,Cho, Shin-Ho,Cho, Seon-Woog 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.3

$Gd_{1-x}VO_4:{Eu_x}^{3+}$ red phosphors were synthesized with changing the concentration of $Eu^{3+}$ ion by using a solid-state reaction method. The crystal structure, surface morphology, and photoluminescence and photoluminescence excitation properties of the red phosphors were measured by using X-ray diffractometer, field emission-scanning electron microscopy, and florescence spectrometer, respectively. The XRD results showed that the main peak of all the phosphor powders occurs at (200) plane. As for the photoluminescence properties, the maximum excitation spectrum occurred at 306 nm due to the charge transfer band from ${VO_4}^{3-}$ to $Eu^{3+}$ ions and the maximum emission spectrum was the red luminescence peaking at 619 nm when the concentration of $Eu^{3+}$ ion was 0.10 mol.

BaMoO₄:Tb³⁺ 형광체의 발광과 농도 소광 특성

조신호,김진대,황동현,조선욱,Cho, Shinho,Kim, Jindae,Hwang, Donghyun,Cho, Seon-Woog 한국재료학회 2016 한국재료학회지 Vol.26 No.2

$BaMoO_4:Tb^{3+}$ phosphor powders were synthesized with different concentrations of $Tb^{3+}$ ions using the solid-state reaction method. XRD patterns showed that all the phosphors, irrespective of the concentration of $Tb^{3+}$ ions, had tetragonal systems with two main (112) and (004) diffraction peaks. The excitation spectra of the $Tb^{3+}$-doped $BaMoO_4$ phosphors consisted of an intense broad band centered at 290 nm in the range of 230-330 nm and two weak bands. The former broad band corresponded to the $4f^8{\rightarrow}4f^75d^1$ transition of $Tb^{3+}$ ions; the latter two weak bands were ascribed to the $^7F_2{\rightarrow}^5D_3$ (471 nm) and $^7F_6{\rightarrow}^5D_4$ (492 nm) transitions of $Tb^{3+}$. The main emission band, when excited at 290 nm, showed a strong green band at 550 nm arising from the $^5D_4{\rightarrow}^7F_5$ transition of $Tb^{3+}$ ions. As the concentration of $Tb^{3+}$ increased from 1 to 10 mol%, the intensities of all the emission lines gradually increased, approached maxima at 10 mol% of $Tb^{3+}$ ions, and then showed a decreasing tendency with further increase in the $Tb^{3+}$ ions due to the concentration quenching effect. The critical distance between neighboring $Tb^{3+}$ ions for concentration quenching was calculated and found to be $12.3{\AA}$, which indicates that dipole-dipole interaction was the main mechanism for the concentration quenching of the $^5D_4{\rightarrow}^7F_5$ transition of $Tb^{3+}$ in the $BaMoO_4:Tb^{3+}$ phosphors.

CaWO₄:Eu³⁺ 형광체의 합성과 발광 특성

조신호,조선욱,Cho, Shin-Ho,Cho, Seon-Woog 한국재료학회 2012 한국재료학회지 Vol.22 No.5

Red phosphors $Ca_{1-1.5x}WO_4:{Eu_x}^{3+}$ were synthesized with different concentrations of $Eu^{3+}$ ions by using a solid-state reaction method. The crystal structure of the red phosphors was found to be a tetragonal system. X-ray diffraction (XRD) results showed the (112) main diffraction peak centered at $2{\theta}=28.71^{\circ}$, and the size of crystalline particles exhibited an overall decreasing tendency according to the concentration of $Eu^{3+}$ ions. The excitation spectra of all the phosphors were composed of a broad band centered at 275 nm in the range of 230-310 nm due to $O^{2-}{\rightarrow}W^{6+}$ and a narrow band having a peak at 307 nm caused by $O^{2-}{\rightarrow}Eu^{3+}$. Also, the excitation spectrum presents several strong lines in the range of 305-420 nm, which are assigned to the 4f-4f transitions of the $Eu^{3+}$ ion. In the case of the emission spectrum, all the phosphor powders, irrespective of $Eu^{3+}$ ion concentration, indicated an orange emission peak at 594 nm and a strong red emission spectrum centered at 615 nm, with two weak lines at 648 and 700 nm. The highest red emission intensity occurred at x = 0.10 mol of Eu3+ ion concentration with an asymmetry ratio of 12.5. Especially, the presence of $Eu^{3+}$ in the $Ca_{1-1.5x}WO_4:{Eu_x}^{3+}$ shows very effective use of excitation energy in the range of 305-420 nm, and finally yields a strong emission of red light.

적색 형광체 Gd_1-xAl₃(BO₃)₄:Eu_x³⁺의 합성과 발광 특성

조신호,조선욱,Cho, Shin-Ho,Cho, Seon-Woog 한국재료학회 2012 한국재료학회지 Vol.22 No.3

Red phosphors of $Gd_{1-x}Al_3(BO_3)_4:{Eu_x}^{3+}$ were synthesized by using the solid-state reaction method. The phase structure and morphology of the phosphors were measured using X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM), respectively. The optical properties of $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors with concentrations of $Eu^{3+}$ ions of 0, 0.05, 0.10, 0.15, and 0.20 mol were investigated at room temperature. The crystals were hexagonal with a rhombohedral lattice. The excitation spectra of all the phosphors, irrespective of the $Eu^{3+}$ concentrations, were composed of a broad band centered at 265 nm and a narrow band having peak at 274 nm. As for the emission spectra, the peak wavelength was 613 nm under a 274 nm ultraviolet excitation. The intensity ratio of the red emission transition ($^5D_0{\rightarrow}^7F_2$) to orange ($^5D_0{\rightarrow}^7F_1$) shows that the $Eu^{3+}$ ions occupy sites of no inversion symmetry in the host. In conclusion, the optimum doping concentration of $Eu^{3+}$ ions for preparing $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors was found to be 0.15 mol.

Eu³⁺ 함량비가 Y<SUB>1-x</SUB>PO₄:Eu<SUB>x</SUB>³⁺ 적색 형광체의 발광 특성에 미치는 영향

조선욱(Seon-Woog Cho),조신호(Shinho Cho) 한국진공학회(ASCT) 2011 Applied Science and Convergence Technology Vol.20 No.6

고상 반응법을 사용하여 Eu³? 이온의 함량비를 변화시키면서 Y1-xPO₄:Eux³? 적색 형광체를 합성하였다. 모든 적색 형광체의 결정 구조는 25.88˚에 중심을 갖는 (200) 주 회절 피크로 구성되는 정방정계이었으며, 결정 입자의 형상은 Eu³? 이온의 함량비가 증가함에 따라 구형에 근접하고 균일한 크기 분포를 나타내었다. 형광 특성의 경우에, Eu³? 이온의 함량비에 관계없이 모든 세라믹은 파장 593.0과 619.2 nm에 피크를 갖는 각각 적주황색과 적색 형광을 나타내었다. Eu³? 이온의 함량비가 증가함에 따라 여기 스펙트럼의 파장은 약간씩 장파장 쪽으로 이동하면서 흡수 세기는 증가하는 경향을 보였으며, Eu³? 이온의 함량비가 0.15 mol일 때 최대 흡수 및 발광 스펙트럼이 관측되었다. Y1-xPO₄:Eux³? red phosphors were synthesized with changing the concentration of Eu³? ion by using a solid-state reaction method. The crystal structures of all the red phosphors were found to be a tetragonal system composed of (200) diffraction peak centered at 25.88˚, and the morphology of grains approached the spherical form with homeogenous size distribution as the concentration of Eu³? ion increased. As for the photoluminescence properties, all of the ceramic phosphors, irrespective of Eu³? ion concentration, showed the red-orange and the red emission peaked at 593.0 and 619.2 nm respectively. As the concentration of Eu³? ion increased, the excitation spectrum moved into a longer wavelength with the increase of emission intensity. The maximum excitation and the emission spectrum were observed at 0.15 mol of Eu³? ion.

라디오파 마그네트론 스퍼터링으로 성장한 질소와 알루미늄 도핑된 ZnO 박막의 특성

조신호(Shinho Cho),조선욱(Seon-Woog Cho) 한국표면공학회 2008 한국표면공학회지 Vol.41 No.4

Nitrogen and aluminum codoped ZnO (NAZO) thin films were grown on glass substrates with changing the nitrogen flow ratio by radio-frequency magnetron sputtering. The structural, optical, and electrical properties of the NAZO films were investigated. The surface morphologies and the structural properties of the thin films were analyzed by using the X-ray diffraction and scanning electron microscopy. The NAZO thin film, deposited at nitrogen flow ratio of 0%, showed a strongly c-axis preferred orientation and the lowest resistivity of 3.2×10?³ Ω㎝. The intensity of ZnO (002) diffraction peak was decreased gradually with increasing the nitrogen flow ratio. The optical properties of the films were measured by UV-VIS spectrophotometer and the optical transmittances for all the samples were found to be an average 90% in the visible range. Based on the transmittance value, the optical bandgap energy for the NAZO thin film deposited at nitrogen flow ratio of 0% was determined to be 3.46 eV. As for the electrical properties, the carrier concentration and the hall mobility were decreased, but the electrical resistivity was increased as the nitrogen flow ratio was increased.

Sm<SUP>3+</SUP> 도핑된 GdVO₄ 형광체의 제조와 발광 특성

조신호(Shinho Cho),조선욱(Seon-Woog Cho) 한국진공학회(ASCT) 2012 Applied Science and Convergence Technology Vol.21 No.2

고상 반응법을 사용하여 Sm<SUP>3+</SUP> 이온의 함량비를 변화시키면서 Gd1-xVO₄:Eux<SUP>3+</SUP> 형광체 분말을 합성하였다. 모든 형광체 시료의 결정 구조는 24.76o에 중심을 갖는 (200) 주 회절 피크로 구성되는 정방정계이었으며, 결정 입자의 형상은 Sm<SUP>3+</SUP> 이온의 함량비가 0.05 ㏖일 때 구형에 근접하고 균일한 크기 분포를 나타내었다. 발광 특성의 경우에, Sm3+ 이온의 함량비에 관계없이 모든 형광체 분말은 파장 565, 603, 645 ㎚에 피크를 갖는 각각 황색, 주황색, 적색 형광을 보였다. Sm<SUP>3+</SUP> 이온의 함량비가 증가함에 따라 흡수 스펙트럼의 세기는 감소하는 경향을 나타내었으며, Sm3+ 이온의 함량비가 0.05 ㏖일 때 최대 흡수와 발광 스펙트럼이 관측되었고, 대칭비의 값은 1.19이었다 Gd1-xVO₄:Smx<SUP>3+</SUP> phosphor powders were synthesized with changing the concentration of Sm<SUP>3+</SUP> ion by using a solid-state reaction method. The crystal structures of all the phosphors were found to be a tetragonal system, composed of (200) diffraction peak centered at 24.76°, and the morphology of grains approached the spherical form with homeogenous size distribution when the concentration of Sm<SUP>3+</SUP> ion was 0.05 ㏖. As for the photoluminescence properties, all of the phosphor powders, irrespective of Sm<SUP>3+</SUP> ion concentration, indicated the yellow, orange, and red emission peaked at 565, 603, and 645 ㎚ respectively. As the concentration of Sm<SUP>3+</SUP> ion increases, the intensity of excitation spectrum showed a decreasing tendency on the increase of Sm<SUP>3+</SUP> ion concentration. The maximum excitation and emission spectra were observed and the symmetry ratio was 1.19 at 0.05 ㏖ of Sm<SUP>3+</SUP> ion.

Eu³⁺ 함량비가 Y_1-xPO₄:Eu_x³⁺ 적색 형광체의 발광 특성에 미치는 영향

조선욱,조신호,Cho, Seon-Woog,Cho, Shin-Ho 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.6

고상 반응법을 사용하여 $Eu^{3+}$ 이온의 함량비를 변화시키면서 $Y_{1-x}PO_4:{Eu_x}^{3+}$ 적색 형광체를 합성하였다. 모든 적색 형광체의 결정 구조는 $25.88^{\circ}$에 중심을 갖는 (200) 주 회절 피크로 구성되는 정방정계이었으며, 결정 입자의 형상은 $Eu^{3+}$ 이온의 함량비가 증가함에 따라 구형에 근접하고 균일한 크기 분포를 나타내었다. 형광 특성의 경우에, $Eu^{3+}$ 이온의 함량비에 관계없이 모든 세라믹은 파장 593.0과 619.2 nm에 피크를 갖는 각각 적주황색과 적색 형광을 나타내었다. $Eu^{3+}$ 이온의 함량비가 증가함에 따라 여기 스펙트럼의 파장은 약간씩 장파장 쪽으로 이동하면서 흡수 세기는 증가하는 경향을 보였으며, $Eu^{3+}$ 이온의 함량비가 0.15 mol일 때 최대 흡수 및 발광 스펙트럼이 관측되었다. $Y_{1-x}PO_4:{Eu_x}^{3+}$ red phosphors were synthesized with changing the concentration of $Eu^{3+}$ ion by using a solid-state reaction method. The crystal structures of all the red phosphors were found to be a tetragonal system composed of (200) diffraction peak centered at $25.88^{\circ}$, and the morphology of grains approached the spherical form with homeogenous size distribution as the concentration of $Eu^{3+}$ ion increased. As for the photoluminescence properties, all of the ceramic phosphors, irrespective of $Eu^{3+}$ ion concentration, showed the red-orange and the red emission peaked at 593.0 and 619.2 nm respectively. As the concentration of $Eu^{3+}$ ion increased, the excitation spectrum moved into a longer wavelength with the increase of emission intensity. The maximum excitation and the emission spectrum were observed at 0.15 mol of $Eu^{3+}$ ion.

태양광 마이크로그리드 융합기술 기초트랙 소개

황동현(Donghyun Hwang),손창식(Chang-Sik Son),조신호(Seon-Woog Cho),조선욱(Shinho Cho),양준영(Junyoug Yang),신종언(Jongeon Shin),최재승(Jaeseung Choi),박상건(Sanggun Park),송진수(Jinsu Song) 한국신재생에너지학회 2017 한국신재생에너지학회 학술대회논문집 Vol.2017 No.5