• Title, Summary, Keyword: Cathodoluminescence

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Colour cathodoluminescence of display materials

  • Nazarov, Michael;Nazarova, Tatiana;Ivannikov, Petr;Saparin, Gennadii
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1580-1583
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    • 2005
  • We report simple new techniques to express analysis of display materials. Colour Cathodoluminescence combined with scanning electron microscopy and spectroscopy is a powerful, non-destructive, high-resolution method for investigation luminescent materials. Some applications of this method to powder phosphors used in display are demonstrated.

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A Study on the Cathodoluminescence and Structure of Thin Film $ZnGa_2O_4:Mn$ Oxide Phosphor (박막형 $ZnGa_2O_4:Mn$ 산화물 형광체의 음극선루미느센스와 구조적 특성에 관한 연구)

  • Kim, Joo-Han;Holloway Paul H.
    • Journal of the Korean Vacuum Society
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    • v.15 no.5
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    • pp.541-546
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    • 2006
  • In this study we have investigated cathodoluminescence (CL) and structural properties of thin film $ZnGa_2O_4:Mn$ oxide phosphor by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), photoluminescence (PL), and cathodoluminescence. PL emission peaked at 506 nm was observed from the $ZnGa_2O_4:Mn$ phosphor target and it was attributed to the $^4T_1-^6A_1$ transition in $Mn^{2+}$ ion. The color coordinates of the emission were x = 0.09 and y = 0.67. The $ZnGa_2O_4:Mn$ films showed the excitation spectrum peaked at 294 nm by $Mn^{2+}$ ion absorption. It was found that the higher intensity of CL emission at 505 nm appears to result from the denser and closely-packed structure in $ZnGa_2O_4:Mn$ phosphor films deposited at lower pressures. The CL intensity did not show any systematic dependence on film surface roughness.

Cathodoluminescence Study of Diamond Films Grown by Cyclic Deposition Method (Cyclic 증착방법에 의해성장된 다이아몬드 박막의 cathodoluminescence 특성에 관한 연구)

  • Seo, Soo-Hyung;Shin, Wan-Chul;Park, Jin-Seok
    • Proceedings of the KIEE Conference
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    • pp.12-15
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    • 2001
  • Polycrystalline diamond films are deposited by cyclic method. modulating the $H_2$ Plasma and $CH_4+H_2$ plasma during the growth step. Diamond quality is evaluated by FWHM and $I_D/I_G$ ratio obtained from Raman spectroscopic analysis. Structural defects and impurities generated during the growth step are characterized by cathodoluminescence, and the variations between band-A(430 nm) line and nitrogen-related(578 nm) line are investigated as a function of $T_E/T_G$. Furthermore, the correlations between preferential orientation. film morphologies and CL characteristics are also investigated.

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Enhanced Cathodoluminescence of KOH-treated InGaN/GaN LEDs with Deep Nano-Hole Arrays

  • Doan, Manh-Ha;Lee, Jaejin
    • Journal of the Optical Society of Korea
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    • v.18 no.3
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    • pp.283-287
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    • 2014
  • Square lattice nano-hole arrays with diameters and periodicities of 200 and 500 nm, respectively, are fabricated on InGaN/GaN blue light emitting diodes (LEDs) using electron-beam lithography and inductively coupled plasma reactive ion etching processes. Cathodoluminescence (CL) investigations show that light emission intensity from the LEDs with the nano-hole arrays is enhanced compared to that from the planar sample. The CL intensity enhancement factor decreases when the nano-holes penetrate into the multiple quantum wells (MQWs) due to the plasma-induced damage and the residues. Wet chemical treatment using KOH solution is found to be an effective method for light extraction from the nano-patterned LEDs, especially, when the nano-holes penetrate into the MQWs. About 4-fold CL intensity enhancement factor is achieved by the KOH treatments after the dry etching for the sample with a 250-nm deep nano-hole array.

Micro-Raman Spectroscopy and Cathodoluminescence Study of Cross-section of Diamond Film

  • Wang, Chun-Lei;Akimitsu Hatta;Jaihyung Won;Jaihyung Won;Nan Jinang;Toshimichi Ito;Takatomo Sasaki;Akio Hiraki;Zengsun Jin
    • The Korean Journal of Ceramics
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    • v.3 no.1
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    • pp.1-4
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    • 1997
  • Diamond film (24$\mu\textrm{m}$) were prepared by Microwave Plasma Chemical Vapor Deposition method from a reactive CO/H$_2$ mixtures. Micro-Raman spectroscopy and micro-cathodoluminescence study were carried out along the crosssection and correlated to SEM observation. CL image of cross-section was also investigated. Peak position, FWHM of Raman spectrum were determined using Lorentzing fit. The stress in this sample is 0.4~0.7 GPa compressive stress, and along the distance the compressive stress reduced. The Raman peak broadening is dominated by phonon life time reduction at grain boundaries and defect sites. Defects and impurities were mainly present inside the film, not at Silicon/Diamond interface.

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Cathodoluminescence Enhancement of CaTiO3:Pr3+ by Ga Addition

  • Kang, Seung-Youl;Byun, Jung-Woo;Kim, Jin-Young;Suh, Kyung-Soo;Kang, Seong-Gu
    • Bulletin of the Korean Chemical Society
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    • v.24 no.5
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    • pp.566-568
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    • 2003
  • The phosphor $CaTiO_3:Pr^{3+}$ attracts much attention as a low-voltage red phosphor because of its good chromaticity and intrinsic conductivity. The addition of Ga into this CaTiO₃:Pr led the luminance intensity to greatly enhance without the change of the wavelength for the electronic transition and the peak shape of it. The increase of the recombination rate of electron-hole pairs through the Ga ion doping, which was expected to play a role of a hole-trap center, is proposed to be one of the reasons for the enhancement of the cathodoluminescence intensity.

Synthesis of ZnO Powder by Precipitation method and Its Cathodoluminescence Properties (침전법에 의한 ZnO 분체합성 및 그 형광특성)

  • 김봉철;박지훈;신효순;이석기;이병교
    • Journal of the Korean Ceramic Society
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    • v.35 no.2
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    • pp.107-114
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    • 1998
  • ZnO powder as phosphor was prepared by precipitation method with zinc acetate and ammonia solution and the size and shapes of precipitates were examined with variation of pH and concentration of solution. Its cathodoluminesence properties was evaluated with various heat tratment condition. Optimum con-dition for uniform precipitates was 11.8 of pH and 0.4M of concentration. ZnO:Zn phosphor was obtained by heat treatment of precipitates in reduction atmosphere using ZnS powder. With addition of 20wt% ZnS and 1 hour firing at 1000$^{\circ}C$ the highest cathodoluminescence was obtained.

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Preparation and Optical Properties of $SrGa_2S_4$:Eu Phosphor

  • Do, Yeong Nak;Bae, Jae U;Kim, Yu Hyeok;Yang, Hong Geun
    • Bulletin of the Korean Chemical Society
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    • v.21 no.3
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    • pp.295-299
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    • 2000
  • The photoluminescence and cathodoluminescence of $SrGa_2S_4:EU$ phosphor were optimized with the process and chemical variables (activators, fluxes and reaction temperature) used in solid state reaction. Firing the powder with flux at $800^{\circ}C$ for 2hr gave the highest photoluminescence efficiency under near-UV excitation and the highest cathodoluminescence efficiency of 20.1 lm/W at 2 kV and 33.3 lm/W at 10 kV. The suitability of $SrGa_2S_4:EU$ for application as a phosphor in LCDs and FEDs is discussed.

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