• 제목/요약/키워드: co-doping

검색결과 408건 처리시간 0.023초

Effect of $Mg^{2+}$ co-doping on luminescent properties of $ZnGa_2O_4:Mn^{2+}$

  • Singh, Binod Kumar;Bartwal, Kunwar Singh;Ryu, Ho-Jin
    • 반도체디스플레이기술학회지
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    • 제6권4호
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    • pp.29-32
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    • 2007
  • Zinc gallate, $ZnGa_2O_4:Mn^{2+}$ co-doped with different concentrations of $Mg^{2+}$ (0.001- 0.5 mol%) was prepared by solid state synthesis method. These compositions were investigated for their photoluminescence and cathodoluminescence properties. The optimized composition $Zn_{0.990}Mg_{0.005}Ga_2O_4:Mn_{0.005}$ shows higher luminescence intensity compared to the parent phosphor. The intense green emission peak was found at 504 nm. The $Mg^{2+}$ doping does not affect much the decay time. It remains <10 ms for these compositions which make them potential candidate for application in TV screens.

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Co-Deposition of Rubrene doped Alq3 film Using Belt Source Evaporation Techniques for Large Size AMOLED

  • Hwang, Chang-Hun;Ju, Sung-Hoo;Park, Myung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1664-1667
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    • 2007
  • The belt source evaporation is for the large size AMOLED devices to re-sublimate the organic film deposited on the metal plate. Using the plane source, the PL spectrum of the doped organic film has been studied for the first time. The PL peak of the pure Alq3 film was 512nm and that of the pure Rubrene was 557nm. The PL peak of the 2% Rubrene doped Alq3 film was shifted to $536{\pm}2nm$. The PL peak wavelength measured at the front surface of the film and at the back surface of the film was measured as nearly same as that the doping ratio maintains uniform within the film thickness. In conclusion, the doping control of the organic film becomes real using the belt type plate sublimation deposition.

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Preparation and Photocatalytic Activity of Multi-elements Codoped TiO2 Made by Sol-gel Method and Microwave Treatment

  • Kim, Sang-Jin;Yun, Seok-Min;Kim, Hyuk;Kim, Jong-Gyu;Lee, Young-Seak
    • Carbon letters
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    • 제10권2호
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    • pp.123-130
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    • 2009
  • Multi-elements doped $TiO_2$ was prepared as a new photocatalyst in order to decrease the band gap of $TiO_2$ by sol-gel process which can provide the large active sites of $TiO_2$. Multi-elements were doped by using a single precursor, tetraethylammonium tetrafluoroborate (TEATFB). By the benefit of large specific surface area of $TiO_2$ prepared by sol-gel process, catalysts showed initial fast removal of dye. The photoactivity showed that the doped catalysts significantly promote the light reactivity than undoped $TiO_2$. The commendable photoactivity of prepared catalysts is predominantly attributable to the doping of anions which may reduce the band gap.

Co2O3 의첨가량이 산화아연 바리스터의 전기적 특성에 미치는 효과 (Co2O3 Doping Effects on the Electrical Properties of ZnO Varistor)

  • 김명식;오명환
    • 대한전기학회논문지
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    • 제34권5호
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    • pp.186-192
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    • 1985
  • Co2O3 additive effects on the electrical properties in ZnO varistor are investigated. As the Co Cations being substituted and ionized normally to a divalent state for Zn in the lattice site increase, the leakage current in the prebreakdown region decreases and the so-called

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Cobalt가 첨가된 이트리아 안정화 큐빅지르코니아(YSZ) 단결정의 리간드장에 따른 색상변화 (Color-change for ligand field of cobalt doped yttria stabilized cubic zirconia (YSZ) single crystal)

  • 석정원;최종건
    • 한국결정성장학회지
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    • 제17권1호
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    • pp.35-40
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    • 2007
  • 스컬(skull)용융법에 의해 성장시킨 코발트($Co^{2+}$)가 도핑(doping)된 $25{\sim}50wt%$의 서로 다른 $Y_2O_3$ 함량을 가진 이트리아 안정화 큐빅지르코니아(YSZ) 단결정을 $N_2$ 분위기 $1000^{\circ}C$에서 5시간 동안 열처리하였다. 적갈색의 단결정들은 각각 보라색 또는 청색으로 변화되었으며, Co가 첨가(doping) 된 처리 전 후의 YSZ들은 직경 6.5, 두께 2 mm의 웨이퍼 또는 직경 10 mm의 라운드브릴리언트 컷(round brilliant cut)으로 연하 하였으며, 광학적 또는 구조적 특성은 UV-VIS 분광광도계와 XRD(X-ray diffraction)로 측정하였으며, $Co^{2+}\;(^4A_2(^4F)\to{^4P})$$Co^{3+}$에 의한 흡수, 에너지 간격(energy gap) 및 격자 매개 변수(lattice parameter)변화가 분석되었다.

Influence of Sn/Bi doping on the phase change characteristics of $Ge_2Sb_2Te_5$

  • Park T.J.;Kang M.J.;Choi S.Y.
    • 정보저장시스템학회논문집
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    • 제1권1호
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    • pp.93-98
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    • 2005
  • Rewritable optical disk is one of the essential data storage media in these days, which takes advantage of the different optical properties in the amorphous and crystalline states of phase change materials. As well known, data transfer rate is one of the most important parameter of the phase change optical disks, which is mostly limited by the crystallization speed of recording media. Therefore, we doped Sn/Bi to $Ge_2Sb_2Te_5$ alloy in order to improve the crystallization speed and investigated the dependence of phase change characteristics on Sn/Bi doping concentration. The Sn/Bi doped $Ge_2Sb_2Te_5$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, UV-visible spectrophotometer, electron probe microanalysis (EPMA), inductively coupled plasma mass spectrometer (ICP-MS) and atomic force microscopy (AFM). Optimum doping concentration of Bi and Sn were 5${\~}$6 at.$\%$ and the minimum time for crystallization was below than 20 ns. This improvement is correlated with the simple crystalline structure of Sn/Bi doped $Ge_2Sb_2Te_5$ and the reduced activation barrier arising from Sn/Bi doping. The results indicate that Sn/Bi might play an important role in the transformation kinetics of phase change materials..

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Ni-Zn ferrite의 Co doping 효과

  • 권윤미;김덕현;이민영;유춘리;이보화
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2013년도 자성 및 자성재료 국제학술대회
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    • pp.59-60
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    • 2013
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