• Title/Summary/Keyword: Electrical Doping

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Effect of $CeO_2$-addition and Particle Size of Doping Material on Characteristic of High-$T_c$ Superconducting Thick Film Using Diffusion Process ($CeO_2$첨가와 도포물질의 입자크기가 화산공정을 이용한 고온초전도 후막의 특성에 미치는 영향)

  • 임성훈;강형곤;홍세은;윤기웅;황종선;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.2
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    • pp.152-157
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    • 2001
  • For the fabrication of YBa$_2$Cu$_3$O$_{x}$ thick film using diffusion process between $Y_3$BaCuO$_{5}$ and BaO+CuO, each material was selected as substrate and doping material. In this paper, we investigated the characteristic of YBa$_2$Cu$_3$O$_{x}$ thick film due to both addition of CeO$_2$into substrate and initial particle size of doping material. Through X-ray diffraction patterns and SEM photographs, the variation of composition and thickness of the formed phase was observed. It was from the experiment obtained that the addition of CeO$_2$into $Y_2$BaCuO$_{5}$ substrate and the initial particle size of doping material play important part in promoting the reaction between substrate and doping material.aterial.

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Characterization Of YBCO HTSC-Thick film With addiction of $CeO_2$ ($CeO_2$첨가에 따른 YBCO고온초전도 후막의 특성)

  • 윤기웅;임성훈;홍세은;강형곤;한용희;한병성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.239-242
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    • 2000
  • To fabricate YBa$_2$Cu$_3$O$_{x}$ thick film using diffusion process, $Y_2$BaCuO$_{5}$ and BaO+CuO as the material of substrate and the doping material were selected. CeO$_2$ in the doping material was mixed. As another doping material, YBa$_2$Cu$_3$O$_{x}$ was prepared for the comparison with BaO+CuO doping material. Each doping material was patterned on $Y_2$BaCuO$_{5}$ substrate by the screen printing method and then was annealed above peritectic reaction temperature of YBCO with a few step. It could be observed by X-ray diffraction patterns and SEM photographs that through the diffusion process of the $Y_2$BaCuO$_{5}$ and BaO+CuO, the YBa$_2$Cu$_3$O$_{x}$ phase was formed. With an amout of addition of CeO$_2$, the thickness of a formed YBa$_2$Cu$_3$O$_{x}$ decreased. x/ decreased.

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발광층에 Dotted-Line Doping Structure(DLDS)를 적용한 Red-Oranic Light-Emitting Diodes(OLEDs)의 발광특성

  • Lee, Chang-Min;Han, Jeong-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.177-180
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    • 2004
  • 발광층에 Alq3와 rubrene을 mixed host로 사용하고 DCJTB를 형광 dopant로 사용한 다층 박막 구조의 red OLEDs를 제작하였다. 소자의 구조는 $ITO:Anode(120nm)/{\alpha}-NPD:HTL(40nm)/Alq_3+Rubrene(mixed\;host\;1:1)+DCJTB(red\;dopant\;3%)+:EML(20nm)/Alq_3:ETL(40nm)/MgAg(Mg\;5%\;wt):Cathode(150nm)$ 로서 EML내부에 DCJTB를 Totally Doping Method와 Dotted-Line Doping Method의 두 가지 방법으로 도핑 하였다. Mixed host구조에 DCJTB를 6구간으로 나누어 Dotted Line Doping한 소자는 luminance yield가 $9.2cd/A@10mA/cm^2$ 이었다. 이 소자는 DCJTB만을 Totally Doping한 소자의 luminance yield $3.2cd/A@10mA/cm^2$에 비해 약 190%정도의 높은 효율 향상을 보였다. 또한 $10mA/cm^2$에 도달하는 전압은 5.5V Vs. 8.5V로서 mixed host를 사용한 소자에서 약 3V정도 구동전압이 낮아지는 효과가 있었다. 발광 스펙트럼의 Full Width Half Maximum(FWHM)은 각각 56.6nm와 61nm로서 rubrene을 mixed host로 사용한 소자에서 높은 색 순도를 얻을 수 있었다. 이러한 성능의 향상은 $Alq_3$와 혼합된 rubrene에 의한 낮은 전하주 입장벽, 높은 전류밀도에서 나타나는 발광감쇄현상의 감소, 그리고 발광층의 DLD구조에 의한 전하의 trap & confinement 에 따른 발광 exciton의 형성확률이 증가한데서 나타났다고 생각된다.

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Improving electroluminescent efficiency of organic light emitting diodes by co-doping (Co-doping을 이용한 OLED의 발광 효율 향상)

  • Park, Young-Wook;Kim, Young-Min;Choi, Jin-Hwan;Ju, Byeong-Kwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.81-82
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    • 2006
  • Doping is a well-known method for improving electroluminescent (EL) efficiency of organic light emitting diodes. In our study, doping with 2 materials simultaneously, we could achieve improved EL efficiency. The emission layer was tris-(8-hydroxyquinoline)aluminum, and the 2 dopants were N,N'-dimethyl-quinacridone (DMQA) and 10-(2-Benzothiazolyl)-2, 3, 6, 7-tetrahydro-1,1,7,7,-tetramethyl 1-1H, 5H, 11H-[1] benzopyrano [6,7,8-ij]quinolizin-11-one (C-545T). The EL intensity of co-doped device was nearly flat, it shows that co-doping technique could be a effective way to improve the EL efficiency. EL efficiency of Single-doped device based on DMQA and C-S45T were ~6.47Cd/A and ~7.45Cd/A, respectively. Co-doped device showed higher EL efficiency of ~8.30Cd/A.

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Synthesis of Nitrogen-Doped Graphene by Thermal Annealing of Graphene Oxide with Melamine Compounds (멜라민 화합물을 이용한 산화 그래핀 도핑 및 특성 평가)

  • Kim, Sumin;Kim, Hyun;Kim, So Yang;Han, Jong Hun
    • Korean Journal of Materials Research
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    • v.29 no.11
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    • pp.677-683
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    • 2019
  • In this paper, nitrogen-doped reduced graphene oxide(rGO) is obtained by thermal annealing of nitrogen-containing compounds and graphene oxide (GO) manufactured by modified Hummers' method. We use melamine as a nitrogen-containing compound and treat GO thermally with melamine at over $800{\sim}1,000^{\circ}C$ and 1 ~ 3 hr under Ar atmosphere. The electrical conductivity of doped rGO is measured by 4-point probe method. As a result, nitrogen contents on rGO are found to be in the range of 2.5 to 12.5 at% depending on the doping conditions after thermal annealing. The main doping site on graphene oxide is changed from pyridinic-N and pyrrolinic N to the graphitic site as the heat treatment temperature increases. The electrical conductivity of doped rGO increases as the N doping content increases. As the thermal treatment time increases, the change of both total doping contents and doping sites is slight and the surface resistance is remarkably reduced, which is caused by healing effects of doped graphene oxide at high temperature.

Enhanced efficiency of organic light-emitting diodes by doping the holetransport layer

  • Kwon, Do-Sung;Song, Jun-Ho;Lee, Hyun-Koo;Shin, You-Chul;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1401-1403
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    • 2005
  • We present that the carrier balance can be improved by doping a hole transport layer of 4,4'- bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl (${\alpha}$-NPD) with a hole blocking material of 2,9-dimethyl- 4,7-diphenyl-1,10-phenanthroline (BCP). The doping leads to disturb hole transport, which can enhance the balance of electron s and holes concentration in the emitting layer, aluminum tris(8 -hydroxyquinoline) (Alq3), resulting in enhanced electroluminescence (EL) quantum efficiency for the device with the doped ${\alpha}$-NPD.

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Nitrogen Doping Characterization of ZnO Prepared by Atomic Layer Deposition (원자층 증착법으로 성장된 ZnO 박막의 질소 도핑에 대한 연구)

  • Kim, Doyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.10
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    • pp.642-647
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    • 2014
  • For feasible study of opto-electrical application regarding to oxide semiconductor, we implemented the N doped ZnO growth using a atomic layer deposition technique. The p-type ZnO deposition, necessary for ZnO-based optoelectronics, has considered to be very difficulty due to sufficiently deep acceptor location and self-compensating process on doping. Various sources of N such as $N_2$, $NH_3$, NO, and $NO_2$ and deposition techniques have been used to fabricate p-type ZnO. Hall measurement showed that p-type ZnO was prepared in condition with low deposition temperature and dopant concentration. From the evaluation of photoluminescence spectroscopy, we could observe defect formation formed by N dopant. In this paper, we exhibited the electrical and optical properties of N-doped ZnO thin films grown by atomic layer deposition with $NH_3OH$ doping source.

The Influence of Silicon Doping on Electrical Characteristics of Solution Processed Silicon Zinc Tin Oxide Thin Film Transistor

  • Lee, Sang Yeol;Choi, Jun Young
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.2
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    • pp.103-105
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    • 2015
  • Effect of silicon doping into ZnSnO systems was investigated using solution process. Addition of silicon was used to suppress oxygen vacancy generation. The transfer characteristics of the device showed threshold voltage shift toward the positive direction with increasing Si content due to the high binding energy of silicon atoms with oxygen. As a result, the carrier concentration was decreased with increasing Si content.

Electrolyte Mechanizm Study of Amorphous Ge-Se Materials for Memory Application (Ge-Se의 스위칭 특성 향상을 위한 Sb-doping에 관한 연구)

  • Nam, Ki-Hyun;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.69-69
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    • 2009
  • In other to progress better crystallization transition and long phase-transformation data of phase-change memory (PRAM), we investigated about the effect of Sb doping and Ag ions percolating into Ge-Se-Te phase-change material. Doped Sb concentrations was determined each of 10 wt%, 20 wt% and 30 wt%. As the Sb-doping concentration was increased, the resistivity decreased and the crystallization temperature increased. Ionization of Ag was progressed by DPSS laser (532 nm) for 1 hour. The resistivity was more decreased and the crystallization temperature was more increased in case of adding Ag layer under Sh-(Ge-Se-Te) thin film. At the every condition of thin films included Ag layer more stable states were indicated compare with just Sh-doped Ge-Se-Te thin films.

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A study on the color change switch and electrochemical doping of polythiophene (Polythiophene의 전기화학적 도핑과 변색 스위치에 관한 연구)

  • 구할본;김주승;김현철;김종욱
    • Electrical & Electronic Materials
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    • v.9 no.2
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    • pp.165-173
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    • 1996
  • We prepared polythiophene and poly(3-methylthiophene) films, known as conducting polymer, by electrochemical method. Polythiophene and poly(3-methylthiophene) films were doped and undoped dopant for the studing the understanding of doping mechanism and possible application to the color change switch. We observed that the anodic, cathodic wave and absorption spectra were slightly changed during doping and undoping process in polythiophene. It shows that doping and undoping process were showed some difference by the appearance and disappearance of polaron and bi-polaron. In the relation of the peak of oxidative current density and potential sweep rate of cyclic voltammograms, the amount of dopant in polythiophene film was homogeneously increased at low scan rate. This also can be applied to the poly(3-methlythiophene).

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