• Title/Summary/Keyword: cathodoluminescence

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Synthesization of ZnO nanomaterials

  • Lee, Jong-Soo;Min, Byung-Don;Kim, Sang-Sig
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.5
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    • pp.1-5
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    • 2003
  • ZnO nanobelts, nanorods, and nanowires were synthesized at three different substrate temperatures from the thermal evaporation of ball-milled ZnO powders at 1380$^{\circ}C$. Transmission electron microscopy (TEM) revealed that the ZnO nanobelts are single crystalline with the growth direction perpendicular to the (010) lattice planes, and that the ZnO nanorods and nanowires are single crystalline with the growth directions perpendicular to the (001) and (110) lattice planes, respectively. In cathodoluminescence (CL), the peak energy of near bandedge (NBE) emission was determined for nanobelts, nanorods, and nanowires.

Cathodoluminescence properties of $Ga_2O_3$ and ZnO nanomaterials ($Ga_2O_3$와 ZnO 나노물질의 CL특성)

  • Lee, Jong-Soo;Kang, Myung-Il;Park, Il-Woo;Sung, Man-Young;Kim, Sang-Sig
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.97-98
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    • 2002
  • $Ga_2O_3$ nanobelts were synthesized from mechanically ground GaN powders with a thermal annealing in a nitrogen atmosphere. The nanobelts are with the range of about $10{\sim}200nm$ width and $10{\sim}50nm$ thickness. Three different ZnO nanomaterials (nanobelts, nanorods, and nanowires) were synthesized at three different substrate temperatures from the thermal evaporation of ball-milled ZnO powders at $1380^{\circ}C$. In cathodoluminescence(CL), the peak energy of near band-edge(NBE) emission was determined for nanobelts, nanorods, and nanowires.

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Synthesis and Cathodoluminescence of Tetrapod and Multipod-shaped ZnO Nanostructures by Oxidation of Zn in Air Atmosphere (공기 중 대기압 분위기에서 Zn의 산화에 의해 생성된 Tetrapod와 Multipod 형태의 나노구조와 음극선 발광 특성)

  • Lee, Geun-Hyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.3
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    • pp.256-260
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    • 2011
  • ZnO nanostructures with tetrapod, needle and multipod shapes were synthesized without catalysts through a simple thermal oxidation of metallic Zn powder in alumina crucible under air atmosphere. X-ray diffraction data revealed that the ZnO nanostructures had wurtzite structure of hexagonal phase. Energy dispersive X-ray (EDX) spectra showed that the ZnO was of high purity. After the oxidation of Zn powder, white colored product was mainly observed and yellow colored product was observed only a very little on the surface of the oxidized source materials. The white product consisted of tetrapods, while yellow product was composed of needles and multipods. Cathodoluminescece spectra showed that the crystalline quality of tetrapods was better that those of needles and multipods.

Growth and characterization of bulk GaN single crystals by basic ammonothermal method (Basic 암모노써멀 방법에 의한 벌크 GaN 단결정의 성장 및 특성)

  • Shim, Jang Bo;Lee, Young Kuk
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.2
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    • pp.58-61
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    • 2016
  • Bulk GaN crystals were grown by the basic ammonothermal method. The c-plane GaN templates grown by hydride vapor phase epitaxy were used as seed crystals and sodium metal, amide, and azide were added as a mineralizer. The growth conditions are at temperatures from $500{\sim}600^{\circ}C$ and pressures from 2~3 kbar. The growth rate for the c-axis was increased with increasing the operating pressure. Average dislocation density was measured $1{\times}10^5/cm^2$ by the cathodoluminescence measurement. The full-width at half-maximum of the X-ray diffraction rocking curve for (002) reflection was approximately 270 arcsec for Ga face and 80 arcsec for N face.