• 한국전기전자재료학회논문지
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• 제15권7호
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• pp.591-596
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• 2002

In this work, epitaxial GaN is grown on sapphire substrate in AlGaN/GaN heterostructures. Deliberate oxygen doping of GaN grown by MOVPE has been studied. The electron concentration increased as a function of the square root of the oxygen partial Pressure. Oxygen is a shallow donor with a thermal ionization energy of $27\pm2 meV$ measured by temperature dependent Hall effects. A compensation ratio of $\theta$=0.3~0.4 was determined from Hall effect measurements. The formation energy of $O_N$ of $E^F$ =1.3eV determined from the experimental data, is lower than the theoretically predicted vague.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.155-155
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• 2010

We have investigated organic light-emitting devices by doping phosphorescent orange and fluorescent blue emitters into the separate layers of single host. The electroluminescence spectra and current efficiency were strongly dependent on the location of each doped layers. The luminance-voltage (L-V) characteristics of the device2 (ITO/Hole Transport Layer/Orange Phosphorescent emissive layer/Blue Fluorescent emissive layer/Electron Transport Layer/liF/Al) showed the maximum current efficiency of 19.5 cd/A.

• 한국전기전자재료학회논문지
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• 제23권4호
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• pp.323-326
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• 2010

$(Zn_{1-x}Ca_x)_2SiO_4$:Mn phosphors doped with Ca were synthesized by solid state reaction method. $(Zn_{1-x}Ca_x)_2SiO_4$:Mn phosphors showed XRD patterns of Willemite structure. Also, $CaSiO_3$ structure and new peak near 610 nm in $(Zn_{1-x}Ca_x)_2SiO_4$:Mn with increasing value of x were observed from XRD and PL. The new peak near 610 nm in $(Zn_{1-x}Ca_x)_2SiO_4$:Mn with doping Ca was attributed to formation of $CaSiO_3$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.69-69
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• 2011

다이아몬드는 절연 물질이지만, 합성 다이아몬드를 생성할 때 결정 내에 도핑(doping) 과정을 통해 불순물을 혼입함으로써 반도체 성질을 가지게 된다. 본 연구에서는 마이크로웨이브 CVD 장치를 이용하여 다이아몬드 박막의 생성 조건을 최적화하고 여기에 다이아몬드 박막 생성시 디보란(Diborane, B2H6)을 주입하여 전기적 특성을 갖는 보론-도핑 된 다이아몬드 박막을 생성하였다. 실험 조건으로는 방전전력 1.4 Kw, 진공압력 40 Torr의 상태에서 디보란의 주입량을 각각 다르게 하여 실험을 진행하였다. 이 때 사용된 기판으로는 전기적 특성이 서로 다른 사파이어($Al_2O_3$), Si, Ti 기판을 사용하여 박막과 기판과의 연관성도 조사하였다. 각각의 보론-도핑 농도와 기판에 따른 다이아몬드 결정구조를 Micro Raman, SEM으로 분석하였고, 다이아몬드 박막의 I-V특성을 통해 다이아몬드의 전기적 특성을 조사하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.216-216
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• 2012

The purpose of this work is to investigate a back surface field (BSF) on variety wafer resistivity for industrial crystalline silicon solar cells. As pointed out in this manuscript, doping a crucible grown Cz Si ingot with Ga offers a sure way of eliminating the light induced degradation (LID) because the LID defect is composed of B and O complex. However, the low segregation coefficient of Ga in Si causes a much wider resistivity variation along the Ga doped Cz Si ingot. Because of the resistivity variation the Cz Si wafer from different locations has different performance as know. In the light of B doped wafer, we made wider resistivity in Si ingot; we investigated the how resistivities work on the solar cells performance as a BSF quality.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.394-394
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• 2011

최근 태양전지의 후면에서 통상적으로 사용되는 Al을 이용한 후면의 BSF형성과 그에 관한 연구보다 계면의 recombination을 줄이기 위하여 passivation 특성이 좋은 층을 후면에 형성하고 국부적으로 BSF를 형성하는 back contact을 형성하여 특성을 향상시키는 연구가 많이 이루어지고 있다. 본 연구는 이러한 local back contact을 boron-BSF를 이용하여 형성하고 passivation layer는 oxide를 이용한 구조를 SILVACO 2-dimension simulation을 이용하여 그 특성을 분석하였다. Boron-local back contact 구조에서 boron-BSF의 doping concentration, depth, lateral width, boron-BSF spacing 가변을 통해 태양전지의 특성변화에 대해서 spectrum response를 통한 QE 분석 및 I-V를 분석하여 최적화하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.820-822
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• 2009

Tandem white organic light emitting diodes (WOLEDs) are fabricated by using a transparent interconnecting layer of Al:LiF composite/molybdenum oxides ($MoO_3$). We demonstrate two types of tandem WOLEDs consisting of two color emissions (red and blue emission) and three color emissions (red, green and blue emission). Tandem WOLED consisting of three color emission shows higher external quantum efficiency and current efficiency.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.771-774
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• 2009

The Improved stability of organic light emitting diodes (OLEDs) containing lithium-quinolate (Liq) as the ETL doping material is investigated. The lifetime could be improved by threefold using the Liq-doped ETL structure. The improvement was attributed to the Liq-doped ETL, which improved hole-electron balance and has a good electrical stability. Additionally, when the Liq doped device was combined with an Mg/Al cathode, the OLED produced a longer lifetime than other device.

• Journal of Magnetics
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• 제10권1호
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• pp.28-32
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• 2005

The magnetic properties and ordering behavior of Nb-doped FePt alloy films prepared by dc-magnetron sputtering were investigated. It was found that Nb addition retarded the ordering reaction from the disordered face-centered-cubic (fcc) Al phase to the ordered face-centered-tetragonal (fct) L1₀ phase. The tetragonality (c/a ratio) of the ordered fct L1₀ phase increased with the Nb concentration. Nb addition hampered c-axis contraction during ordering, probably because the larger Nb atoms occupy Pt sites. Consequently, the coercivity and magnetocrystalline anisotropic energy of Nb-doped FePt alloy films are lower than those of un-doped FePt film under equivalent annealing conditions.

• 태양에너지
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• 제19권1호
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• pp.29-36
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• 1999

ZnO/n-Si junctions were fabricated by spin coating with ZnO precursor produced by the sol-gel process. In order to increase the electrical conductivity of ZnO films, the films were n-doped with Al impurity and subsequently annealed at about $450^{\circ}C$ under reducing environments. The ohmic contacts between n-Si and AI for a bottom electrode were successfully fabricated by doping the rear surface of Si substrate with phosphorous atoms. The front surface of the substrate was also doped with phosphorous atoms for improving the efficiency of the solar cells. Consequently, conversion efficiencies ranging up to about 5.3% were obtained. These efficiencies were found to decrease slowly with time because of the oxide films formed at the ZnO/Si interface upon oxygen penetration through the porous ZnO. Oxygen barrier layers could be necessary in order to prevent the reduction of conversion efficiencies.