• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.289-292
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• 2005

New poly-Si TFTs have been proposed and fabricated in order to increases the output channel resistance ($r_o$). The counter-doped($p^+$) source is tied to the $n^+$ source and is extended into the channel region so that it employs the reverse bias depletion in the channel. As $V_{DS}$ is increased, the depletion width is increased and the effective channel width is reduced. Therefore, the output current saturates well and the $r_o$ is increased successfully. The proposed CMOS devices may improve the amplifier gain of data driver in active-matrix displays

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
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• pp.194-197
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• 2006

Lead-free bismuth-layered perovskite ferroelectric europium-substituted $Bi_{4}Ti_{3}O_{12}(BTO)$ thin films have been successfully deposited on Pt/Ti/$SiO_2$/Si substrate by a sol-gel spin-coating process. $Bi(TMHD)_3,\;Eu(THMD)_3,\;Ti(OiPr)_4$ were used as the precursors, which were dissolved in 2-methoxyethanol. The thin films were annealed at various temperatures from $600^{\circ}\;to\;720^{\circ}C$ in oxygen ambient for 1 hr, which was followed by post-annealed for 1 hr after depositing a Pt electrode to enhance the electrical properties. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the crystallinity and surface morphology of layered perovskite phase, respectively. The remanent polarization value of the BET thin films annealed at $720^{\circ}C\;was\;25.95{\mu}C/cm^2$ at an applied voltage of 5 V.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.236.1-236.1
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• 2015

The surface morphology of front transparent conductive oxide (TCO) films is very important to achieve high current density in amorphous silicon (a-Si) thin film solar cells since it can scatter the light in a better way. In this study, we present the low cost hydrothermal deposited uniform zinc oxide (ZnO) nano-flower structure with various aspect ratios for a-Si thin film solar cells. The ZnO nano-flower structures with various aspect ratios were grown on the RF magnetron sputtered AZO films. The diameters and length of the ZnO nano-flowers was controlled by varying the annealing time. The length of ZnO nano-flowers were varied from 400 nm to $2{\mu}m$ while diameter was kept higher than 200 nm to obtain different aspect ratios. The ZnO nano-flowers with higher surface area as compared to conventional ZnO nano structure are preferred for the better light scattering. The conductivity and crystallinity of ZnO nano-flowers can be enhanced by annealing in hydrogen atmosphere at 350 oC. The vertical aligned ZnO nano-flowers showed higher haze ratio as compared to the commercially available FTO films. We also observed that the scattering in the longer wavelength region was favored for the high aspect ratio of ZnO nano-flowers. Therefore, we proposed low cost and vertically aligned ZnO nano-flowers for the high performance of thin film solar cells.

• 센서학회지
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• 제8권3호
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• pp.274-282
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• 1999

암모니아가스에 민감한 In이 도핑된 ZnO(ZnO:In) 박막을 In 박막($100\;{\AA}$) 및 ZnO박막($3000\;{\AA}$)의 연속적인 증착과 열처리공정을 통하여 제조하였다. 기판은 $1000\;{\AA}$의 산화막이 열적으로 성장되어 있는 Si 기판을 사용하였다. In/ZnO 박막 이중층의 열처리온도에 따른 구조적 및 전기적 특성을 X-선회절기, 주사전자현미경 및 4점측정시스템을 통하여 조사하였다. 이들 막에 대하여 열처리온도에 따른 암모니아가스에 대한 감도, 선택성 및 시간응답특성을 구하였다. 열처리온도 $400^{\circ}C$, 동작온도 $300^{\circ}C$에서 100 ppm의 암모니아가스를 주입한 결과 140%의 최대감도를 나타내었으며 CO, $NO_x$ 가스에 대한 감도는 아주 낮은 것으로 나타났다.

• 한국세라믹학회지
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• 제22권2호
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• pp.11-16
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• 1985

The semiconducting ceramics having positive temperature coefficient of resistivity in he family of 0.25mol% $Sb_2O_3$ doped barium titanates were prepared with AST ($4Al_2O_3$.$9SiO_2$.$3TiO_2$) and $MnO_2$ as additives and these electrical properties were investigated. The PTCR characteristic in these ceramic materials was improved by the addition of AST and $MnO_2$ because the addition of AST decreased the room temperature resistivity and controlled grin size due to the formation of a liquid phase during sintering and the addition of $MnO_2$ improved by forming acceptor level on the intergranular layer. On dependence on the switching time as switching temperature was increased the initial power and switching time increased.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.124.2-124.2
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• 2011

현재 박막형 태양전지는 실리콘계가 주류를 이루고 있으며, 유리기판 또는 유연성 기판에 비정질 실리콘 박막을 형성시킨 태양전지와 실리콘 기판 양면에 태양전지를 형성하는 방법 등 효율을 극대화시킨 이종접합 태양전지 등이 연구되고 있다. 예컨대 밴드갭이 서로 다른 박막들 간의 이종접합을 이용한 tandem 구조 및 triple 구조의 Si 박막 태양전지의 경우 13%대 변환효율을 나타낸다고 보고된 바 있다. 본 연구에서는 비정질 Si 박막 태양전지 내 흡수층의 효율을 최대화하기 위하여 AZO/Ag 이중구조 박막의 특성에 관한 연구를 수행하고자 한다. combinatorial sputtering system을 이용하여 AZO/Ag 이중구조 박막을 제작하였으며 타겟으로는 4-inch target(Ag, 2wt% Al2O3 doped ZnO)이 사용되었다. 유리기판 상에 combinatorial sputter system으로 상온에서 제작된 Ag 박막의 두께는 25nm로 성장시켰으며 연속공정으로 AZO 박막을 제작하였고, AZO 박막은 100~500nm의 두께경사를 나타내었다. 이 때 유리기판상에 성장된 Ag/AZO 박막의 면저항은 약 $2{\Omega}/{\Box}$ 값을 나타내었다. 본 발표에서는 AZO/Ag 이중 구조 박막의 우수한 전기적 특성을 기반으로 표면 거칠기 및 반사도 특성 등에 관하여 추가적으로 토론한다.

• 대한금속재료학회지
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• 제50권8호
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• pp.557-562
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• 2012

Self-organized ruthenium (Ru) dots were fabricated by $400^{\circ}C$ RTA (rapid thermal annealing) and ALD (atomic layer deposition). The dots were produced under the $400^{\circ}C$ RTA conditions for 10, 30 and 60 seconds on all Si(100)/200 nm-SiO2, glass, and glass/fluorine-doped tin oxide (FTO) substrates. Electrical sheet resistance, and surface microstructure were examined using a 4-point probe and FE-SEM (field emission scanning electron microscopy). Ru dots were observed when a 30 nm-Ru layer on a Si(100)/200 nm-SiO2 substrate was annealed for 10, 30 and 60 seconds, whereas the dots were only observed on a glass substrate when a 50 nm-Ru layer was annealed on glass. For a glass/FTO substrate, RTA <30 seconds was needed for 30 nm Ru thick films. Those dots can increase the effective surface area for silicon and glass substrates by up to 5-44%, and by 300% for the FTO substrate with a < $20^{\circ}$ wetting angle.

• 한국태양에너지학회 논문집
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• 제39권1호
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• pp.33-40
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• 2019

Al-doped ZnO (AZO) thin films were synthesized on Si(100) wafers via plasma enhanced metal organic chemical vapor deposition (PE-MOCVD) method using diethyl zinc (DEZ) and N-methylpyrrolidine alane (MPA) as precursors. Effects of Al/Zn mixing ratio, plasma power on the surface morphology, crystal structure, and electrical property were investigated with SEM, XRD and 4-point probe measurement respectively. Growth rate of the film decreased slightly with increasing the Al/Zn mixing ratio, however electrical property was enhanced and resistivity of the film decreased greatly about 2 orders from $9.5{\times}10^{-1}$ to $8.0{\times}10^{-3}{\Omega}cm$ when the Al/Zn mixing ratio varied from 0 to 9 mol%. XRD analysis showed that the grain size increased with increasing the Al/Zn mixing ratio. Growth rate and electrical property were enhanced in a mild plasma condition. Resistivity of AZO film decreased down to $7.0{\times}10^{-4}{\Omega}cm$ at an indirect plasma of 100 W condition which was enough value to use for the transparent conducting oxide (TCO) material.

• 센서학회지
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• 제31권6호
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• pp.371-375
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• 2022

Antimony-doped tin oxide (ATO) thin films, one type of transparent conductive oxide (TCO) films, were prepared on a SiO₂-coated glass substrate with different substrate temperatures by a radio-frequency magnetron sputtering system. Structural, optical, and electrical characteristics of the deposited ATO films were analyzed using X-ray diffraction, scanning electron microscopy, alpha-step, ultraviolet-visible spectrometer, and Hall effect measurement. The substrate temperature during deposition did not affect the basic crystal structure of the films but changed the grain size and film thickness. The optical transmittance of the ATO films deposited at different substrate temperatures was over 70%. The lowest sheet resistance and resistivity were 8.43 × 10² Ω/sq, and 0.3991 × 10^-2 Ω·cm, respectively, and the highest carrier concentration and mobility were 2.36 × 10²¹ cm^-3 and 6.627 × 10^-2 cm²V^-1s^-1, respectively, at a substrate temperature of 400 ℃.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.243-247
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• 2012

The paper focuses on an anti-reflection (AR) coating deposited by PECVD in silicon solar cell fabrication. AR coating is effective to reduce the reflection of the light on the silicon wafer surface and then increase substantially the solar cell conversion efficiency. In this work, we carried out experiments to optimize double AR coating layer with silicon nitride and silicon oxide for the silicon solar cells. The p-type mono crystalline silicon wafers with $156{\times}156mm^2$ area, 0.5-3 ${\Omega}{\cdot}cm$ resistivity, and $200{\mu}m$ thickness were used. All wafers were textured in KOH solution, doped with $POCl_3$ and removed PSG before ARC process. The optimized thickness of each ARC layer was calculated by theoretical equation. For the double layer of AR coating, silicon nitride layer was deposited first using $SiH_4$ and $NH_3$, and then silicon oxide using $SiH_4$ and $N_2O$. As a result, reflectance of $SiO_2/SiN_x$ layer was lower than single $SiN_x$ and then it resulted in increase of short-circuit current and conversion efficiency. It indicates that the double AR coating layer is necessary to obtain the high efficiency solar cell with PECVD already used in commercial line.