Photoluminescence characteristics of epitaxially grown ZnGa₂O₄thin film phosphors on MgO(100) substrates

Yi, Soung-Soo 신라대학교 자연과학연구소 2004 自然科學論文集 Vol.13 No.-

ZnGa_(2)O_(4) thin film phosphors have been epitaxially deposited using a pulsed laser deposition technique on MgO(001) substrates at several substrate temperatures of 350, 450 and 550℃ with a fixed oxygen pressure 100 mTorr. The films grown under different deposition conditions have been characterized bymicrostructural and luminescent measurements. Under the different substrate temperatures, ZnGa_(2)O_(4) thin films show the different crystallinity and luminescent intensity. The photoluminescence (PL) spectra show a broad band which extends from 350 to 600 nm, peak at 460 nm. The PL brightness obtained from the ZnGa_(2)O_(4) films grown under optimized conditions have indicated that the MgO(100) is one of the most promising substrate for the growth of high quality ZnGa_(2)O_(4) thin film phosphor.

Photoluminescence of ZnGa₂O_4-xM_x:Mn²⁺ (M=S, Se) Thin Films

Yi, Soung-Soo The Korean Institute of Electrical and Electronic 2003 Transactions on Electrical and Electronic Material Vol.4 No.6

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.

Crystalline-phase-dependent luminescence behaviors of Gd2O3:Eu3+ thin film phosphors grown on Si (100) substrates

Soung Soo Yi 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.3

Gd2O3 : Eu3+ luminescent thin lms were grown on Si (100) substrates by using pulsed-laser deposition. The lms grown at dierent deposition conditions showed dierent crystalline phases, surface morphologies and luminescent characteristics. Both cubic and monoclinic crystalline phases were observed for the Gd2O3 : Eu3+ lms, and the crystalline structure and the surface morphology of the lms were highly dependent on the oxygen pressure. The luminescence characteristics were strongly in uenced by the crystalline structure and the surface roughness of the lms. The photoluminescence brightness data obtained from the Gd2O3 : Eu3+ lms indicatedd that Si (100) is a promising substrate for growth of high-quality Gd2O3 : Eu3+ thin-lm red phosphors. In particular, the Gd2O3 : Eu3+ lms showed a much better photoluminescence behavior than Y2O3 : Eu3+ lms with the same thickness, demonstrating that Gd2O3 : Eu3+ lms are promiseing for applications to at panel displays.

Photoluminescence Properties of Li+-doped KNbO3:Eu3+ Phosphors

Yi, Soung Soo,Balakrishnalah, R.,Kim, Dong Woo,Jang, Kiwan,Lee, Ho Sueb,Kim, Sung Hoon,Moon, Byung Kee,Jeong, Jung Hyun Korean Physical Society 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.6

Photoluminescence of Li-doped Y_2O_3:Eu^3+ thin film phosphors grown by pulsed laser deposition

Yi, Soung-Soo 한국센서학회 2002 센서학회지 Vol.11 No.6

Y_2O_3:Eu^3+ and Li-doped Y_2O_3:Eu^3+ thin films have been grown on sapphires substrate using a pulsed laser deposition technique. The thin film phosphors were deposited at a substrate temperature of 600℃ under the oxygen pressure of 100, 200 and 300 mTorr. The films grown under different deposition conditions have been characterized using microstructural and luminescent measurements. The crystallinity and photoluminescence (PL) of the films are highly dependent on the oxyen pressure. The PL brightness data obtained from Y_2O_3:Eu^3+ films grown under optimized conditions have indicated that sapphire is one of the most promising substrate for the growth of high quality Y_2O_3:Eu^3+ thin film red phosphor. In particular, the incorporation of Li^+ ions into Y_2O_3 lattice could induce a remarkable increase of PL. The highest emission intensity was observed with LiF-doped Y_1.84Li_0.08Eu_0.08O_3(Y_2O_3LiEu), Whose brightness was increased by a factor of 2.7 in comparison with that of Y_2O_3:Eu^3+ films. This phosphor may promise for application to the flat panel displays.

PLD 방법으로 Al2O3(0001) 기판 위에 증착한 Y2O3:Eu(3+) 박막의 형광 특성

이성수 ( Soung Soo Yi ) 한국센서학회 2004 센서학회지 Vol.13 No.3

N/A Y₂O₃:Eu^(3+) thin films have been grown on Al₂O₃ (0001) substrates by a pulsed laser deposition (PLD) method. The phosphor thin films were deposited at a substrate temperature of 500, 600, and 700℃ under the oxygen pressure of 100. 200, and 300 mTorr. The crystallinity, surface roughness and photoluminescence of the films are highly dependent on the substrate temperature and oxygen pressure. The films grown on Al₂O₃ (0001) substrate even under the different substrate temperatures and oxygen pressures exhibited (222) preferred orientation. The luminescent spectra exhibited strong luminescence of ^(5)D_(0)-^(7)F₂ transition within Eu^(+3) peaking at 612 nm. The crystallinity and luminescence intensity of the films have been improved as the substrate temperature increasing. With increase of oxygen pressure from 50 to 300 mTorr; the crystallinity of the films has been uniformly decreased. The photoluminescence intensity and surface roughness have similar behaviors as a function of oxygen pressure. At 200 mTorr, both photoluminescence intensity and surface roughness show a maximum.

Al_2O_3 기판위에 증착한 ZnGa_2O_4 형광체 박막의 산소분압에 따른 형광특성

이성수 한국센서학회 2002 센서학회지 Vol.11 No.2

ZnGa_2_O4 형광체 박만을 기판 온도를 550℃ 에 고정시키고 산소 분압을 100, 200, 300 mTorr로 변화시키며 Al_2O_3(0001) 기판 위에 펄스 레이저 증착법을 이용하여 증착하였다. 다른 산소 분압에서 성장한 박막들의 미세 결정구조와 형광특성을 조사하였으며, 산소분압이 증가할수록 박막의 결정성이 변화하였으며 박막의 조성비가 다름을 형광특성을 통하여 알 수 있었다. 발광 스펙트럼은 460 nm에서 최고 피크값을 나타내었으며, 300 nm에서 600 nm까지 갖는 넓은 밴드의 형광 특성을 나타내었다. 최적의 조건에서 성장된 박막의 형광 밝기를 고려해볼 때 Al_2O_3(0001) 기판이 우수한 ZnGa_2_O4 형광체 박막을 성장시킬 수 있는 기판들 중 하나임을 확인하였다. ZnGa_2_O4 thin film phosphors have been deposited using a pulsed laser deposition technique on Al_2O_3(0001) substrates at a substrate temperature of 550 ℃ with various oxygen pressures 100, 200 and 300 mTorr. The films grown under different growth oxygen pessures have been characterized using microstructural and luminescent measurements. The different photoluminescence (PL) characteristics with the increase in oxygen pressures may result from the change of the crystallinity and the composition ratio of Zn and Ga in the films. The luminescent spectra show a broad band extending from 300 to 600 nm peaking at 460 nm. The PL brightness data obtained from the ZnGa_2_O4 films grown under optimized conditions have indicated that the sapphire is a promising substrate for the growth of high quality ZnGa_2_O_4 thin film phosphor.

Al₂O₃ 기판위에 증착한 ZnGa₂O₄ 형광체 박막의 산소분압에 따른 형광특성

이성수,Yi, Soung-Soo 한국센서학회 2002 센서학회지 Vol.11 No.2

$ZnGa_2O_4$ 형광체 박막을 기판 온도를 $550^{\circ}C$에 고정시키고 산소 분압을 100, 200, 300 mTorr로 변화시키며 $Al_2O_3$(0001) 기판 위에 펄스 레이저 증착법을 이용하여 증착하였다. 다른 산소 분압에서 성장한 박막들의 미세 결정구조와 형광특성을 조사하였으며, 산소분압이 증가할수록 박막의 결정성이 변화하였으며 박막의 조성비가 다름을 형광특성을 통하여 알 수 있었다. 발광 스펙트럼은 460 nm에서 최고 피크값 을 나타내었으며, 300 nm에서 600 nm까지 갖는 넓은 밴드의 형광 특성을 나타내었다. 최적의 조건에서 성장된 박막의 형광 밝기를 고려해볼 때 $Al_2O_3$(0001) 기관이 우수한 $ZnGa_2O_4$ 형광체 박막을 성장시킬 수 있는 기판들 중 하나임을 확인하였다. $ZnGa_2O_4$ thin film phosphors have been deposited using a pulsed laser deposition technique on $Al_2O_3$(0001) substrates at a substrate temperature of $550^{\circ}C$ with various oxygen pressures 100, 200 and 300 mTorr. The films grown under different growth oxygen pressures have been characterized using microstructural and luminescent measurements. The different photoluminescence (PL) characteristics with the increase in oxygen pressures may result from the change of the crystallinity and the composition ratio of Zn and Ga in the films. The luminescent spectra show a broad band extending from 300 to 600 nm peaking at 460 nm. The PL brightness data obtained from the $ZnGa_2O_4$ films grown under optimized conditions have indicated that the sapphire is a promising substrate for the growth of high quality $ZnGa_2O_4$ thin film phosphor.

후열처리 온도에 따른 ZnGa₂O₄ 형광체 박막의 발광 특성

이성수,정중현,Yi, Soung-Soo,Jeong, Jung-Hyun 한국센서학회 2002 센서학회지 Vol.11 No.1

$ZnGa_2O_4$박막 형광체는 기판 온도 $550^{\circ}C$, 산소 분압 100mTorr에서 Si(100) 기판 위에 펄스레이저 증착법을 이용하여 증착시켰고, 이렇게 증착되어진 박막을 $600^{\circ}C$와 $700^{\circ}C$에서 후 열처리하여 발광 특성을 조사하였다. X-선 회절 실험 결과, 후열처리 온도를 증가시킴에 따라서 $Ga_2O_3$ 상이 나타남을 확인할 수 있었다. 발광 스펙트럼은 460nm에서 최고 피크값을 나타내었으며. 350에서 600nm까지 갖는 넓은 밴드의 발광 특성을 나타내었다. 후열처리에 따른 $ZnGa_2O_4$ 박막은 다른 형태의 발광 강도와 grain 크기를 나타내었다. $ZnGa_2O_4$ thin film phosphors have been deposited using a pulsed laser deposition method on Si(100) substrates at a substrate temperature of $550^{\circ}C$ with oxygen pressures of 100mTorr, and subsequently to investigate their photoluminescence characteristics after post-annealed at $600^{\circ}C$ and $700^{\circ}C$. As a result for X-ray diffraction, $Ga_2O_3$ shape appeared with increasing annealing temperature. The luminescent spectra show a broad band extending from 350 to 600nm peaking at 460nm. A post-annealing treatment of $ZnGa_2O_4$ thin films led to the different shape of luminescent intensity and grain size.

Luminescence and thermal-quenching properties of Dy3+-doped Ba2CaWO6 phosphors

Yu, Ruijin,Shin, Dong Soo,Jang, Kiwan,Guo, Yue,Noh, Hyeon Mi,Moon, Byung Kee,Choi, Byung Chun,Jeong, Jung Hyun,Yi, Soung Soo Elsevier 2014 Spectrochimica acta. Part A, Molecular and biomole Vol.125 No.-

A series of new double perovskite tungstate Ba2CaWO6:xDy(3+) (0.01 <= x <= 0.15) phosphors were synthesized via solid state reaction process. XRD analysis confirmed the phase formation of Ba2CaWO6:Dy3+ materials. The photoluminescence excitation and emission spectra, concentration effect, thermal-quenching, and decay property were investigated. The phosphor could be excited by the UV light region from 250 to 400 nm, and it exhibits blue (493 nm) and yellow (584 nm) emission corresponding to F-4(9/2)-H-6(15/2) transitions and F-4(9/2)-H-6(13/2) transitions, respectively. The optimum dopant concentration of Dy3+ ions in Ba2CaWO6:xDy(3+) is around 5 mol% and the critical transfer distance of Dy3+ is calculated as 14 angstrom. The thermal-quenching temperature is 436 K for Ba2CaWO6:0.05Dy(3+). The fluorescence lifetime is also determined in Ba2CaWO6:0.05Dy(3+). (C) 2014 Elsevier B.V. All rights reserved.