• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.426.1-426.1
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• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• 한국전기전자재료학회논문지
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• 제18권8호
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• pp.708-713
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• 2005

An alumina membrane with nano-sized pore array by anodic oxidation using the thin film aluminum deposited on silicon wafer was fabricated. It Is important that the sample prepared by metal deposition method has a flat aluminum surface and a good adhesion between the silicon wafer and the thin film aluminum. The oxidation time was controlled by observation of current variation. While the oxalic acid with 0.2 M was used for low voltage anodization under 100 V, the chromic acid with 0.1 M was used for high voltage anodization over 100 V. The nano-sized pores with diameter of $60\~120$ nm was obtained by low voltage anodization of $40\~80$ V and those of $200\~300$ nm was obtained by high voltage anodization of $140\~200$ V. The pore widening process was employed for obtaining the one-channel with flat surface because the pores of the alumina membrane prepared by the fixed voltage method shows the structure of two-channel with rough surface. Finally, the sample was immersed to the phosphoric acid with 0.1 M concentration to etching the barrier layer.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.27-32
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• 2004

High temperature superconducting coated conductor has a structure of /< superconducting layer>//. The buffer layer consists of multi layer, and the architecture most widely used in RABiTS approach is CeO$_2$(cap layer)/YSZ(diffusion barrier layer)/CeO$_2$(seed layer). Evaporation technique is used for the CeO$_2$ layer and DC reactive sputtering technique is used for the YSZ layer, A chamber was set up specially for DC reactive sputtering, Detailed features are as following. A separator divided the chamber into two halves a sputtering chamber and a reaction chamber. The argon gas for sputtering target elements flows out of the cap of sputtering gun, and water vapor for reaction with depositing species spouts near the substrate. Turbo pump is connected with reaction chamber. High speed deposition of YSZ film could be achieved in the chamber. Detailed deposition conditions (temperature and partial pressure of reaction gas) were investigated for the rapid growth of high quality YSZ film.

• 한국응용과학기술학회지
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• 제17권1호
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• pp.29-35
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• 2000

In this study, ultra-thin films of (N-docosyl quinolinium)-TCNQ(1:2) complex were prepared on the hydrophilic substrate by Langmuir-Blodgett(LB) technique. The characteristics of ${\pi}-A$ isotherms were studied to find optimum conditions of deposition by varying temperature of subphase, compression speed of barrier and amount of spreading solution. Using UV-vis spectra, capacitance and thickness, deposition of LB films was confirmed together with the thickness of the naturally oxidized aluminum film inside a device and dielectric constant of (N-docosyl quinolinium)-TCNQ(1:2) complex. The dielectric constant of LB film was about $4.59{\sim}5.58$. The electrical properties of (N-docosyl quinolinium)-TCNQ(1:2) complex were investigated at room temperature. The conductivity of this film measured by the direction of either vertical or horizontal axis was found to have a quite different value.

• 신재생에너지
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• 제2권3호
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• pp.31-36
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• 2006

Superstrate pin amorphous silicon thin-film(a-Si:H) solar cells are prepared on $SnO_2:F$ and ZnO:Al transparent conducting oxides(TCO) in order to see the effect of TCO/p-layers on a-Si:H solar cell operation. The solar cells prepared on textured ZnO:Al have higher open circuit voltage VOC than cells prepared on $SnO_2:F$. Presence of thin microcrystalline p-type silicon layer(${\mu}c-Si:H$) between ZnO:Al and p a-SiC:H plays a major role by causing improvement in fill factor as well as $V_{OC}$ of a-Si:H solar cells prepared on ZnO:Al TCO. Without any treatment of pi interface, we could obtain high $V_{OC}$ of 994mV while keeping fill factor(72.7%) and short circuit current density $J_{SC}$ at the same level as for the cells on $SnO_2:F$ TCO. This high $V_{OC}$ value can be attributed to modification in the current transport in this region due to creation of a potential barrier.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1352-1353
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• 2008

In this study, aluminium - doped zinc oxide (ZnO:Al) transparent conducting film was deposited on PET(polyethylen terephthalate) substrate by r.f. magnetron sputtering method. PET substrate was surface-treated in an atmospheric pressure DBD(dielectric barrier discharge) plasma to increase deposition rate and to improve electrical propesties. Morphological changes by DBD plasma were obsered using contact angle measurement. The contact angle of water on PET was reduced from 62$^{\circ}$ to 42$^{\circ}$ by DBD plasma surface treatment. The plasma treatment also increased deposition rate and electrical propesties. The electrical resistivity as low as $4.97{\times}10^{-3}[{\Omega}-cm]$ and the deposition rate of 234[${\AA}$-m/min] were obtained in ZnO:Al film with surface treatment time of 5min, and 20min., respectively.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.198.2-198.2
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• 2014

We investigated change of the electronic structure, chemical states and elements ratio in graphene film by using photoelectron spectroscopy (PES). The graphene electrode has attracted considerable interest due to its possible applications in flexible organic light emitting diodes (F-OLEDs). However, to use the graphene for OLEDs, sufficient increase of work function is required, that is related with hole injection barrier. Plasma treatment is one of the most widely used method in OLEDs to increase the work function of the anode such as indium tin oxide (ITO). In this work, we used the plasma treatment, which is generated by various gas types such as O2, and Ar to increase the work function of the graphene film. From these results, we discuss the relation among the change of work function, plasma power, plasma treatment time and gas types.

• Journal of Korean Vacuum Science & Technology
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• 제5권2호
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• pp.47-51
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• 2001

To obtain high remnant polarization and good crystalinity of ferroelectric thin films in non-volatile memory devices, the high temperature treatment in oxygen ambient is inevitable. Severe problems that occur in this process are oxygen diffusion into substrate, oxidation of electrode and buffer layer, degradation of microstructure and so on. We made ruthenium dioxide thin film by reactive sputtering with oxygen and argon mixture atmosphere. Comparing quantitatively the core-level spectra of Ru and RuO$_2$ obtained by x-ray photoelectron spectroscopy(XPS), we found that chemical state of RuO$_2$ is very stable and of good resistance to oxygen diffusion and oxidation of adjacent layers. It opens the use of RuO$_2$ thin film as a multifunctional layer of good conducting electrode and resistive barrier for the diffusion and the oxidation. We also suggest a correct understanding of Ru 3d core-level spectrum for RuO$_2$ based on the scheme of final state screening and charge transfer satellites.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.158-161
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• 2006

Superstrate pin amorphous silicon thin-film (a-Si:H) solar cells are prepared on $SnO_2:F$ and ZnO:Al transparent conducting oxides (TCO) In order to see the effect of TCO/P-layers on a-Si:H solar cell operation. The solar cells prepared on textured ZnO:Al have higher open circuit voltage $V_{oc}$ than cells prepared on $SnO_2:F$. Presence of thin microcrystalline p-type silicon layer $({\mu}c-Si:H)$ between ZnO:Al and p a-SiC:H plays a major role by causing improvement in fill factor as well as $V_{oc}$, of a-Si:H solar cells prepared on ZnO:Al TCO. Without any treatment of pi interface, we could obtain high $V_{oc}$, of 994mv while keeping fill factor (72.7%) and short circuit current density $J_{sc}$ at the same level as for the cells on $SnO_2:F$ TCO. This high $V_{oc}$ value can be attributed to modification in the current transport in this region due to creation of a potential barrier.

• 한국재료학회지
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• 제5권2호
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• pp.169-177
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• 1995

Cu와 Si사이의 확산방지막으로 1000$\AA$ 두께의 TiN의 특성에 대하여 면저항 측정, 식각패임자국 관찰, X선 회절, AES, TEM 등을 이용하여 조사하였다. TiN 확산방지막은 $550^{\circ}C$, 1시간의 열처리 후에 Cu의 안쪽 확산으로 인해 Si(111)면을 따라 결정결함(전위)을 형성하고, 전위 주위에 Cu 실리사이드로 보이는 석출물들을 형성함으로써 파괴되었다. Al의 경우와는 달리 Si 패임자국이 형성되지 안흔 것으로부터 TiN확산방지막의 파괴는 Cu의 안쪽 확산에 의해서만 일어나는 것을 알 수 있었다. 또한, Al의 경우에는 우수한 확산방지막 특성을 보여주었던 충진처리된 TiN가 Cu의 경우에는 거의 효과가 없는 것을 알 수 있었다. 이것은 Al의 경우에는 TiN의 결정립계에 존재하는 $TiO_{2}$가 Al과 반응하여 $Al_{2}O_{3}$를 형성함으로써 Al의 확산을 방해하는 화학적 효과가 매우 크지만, Cu의 경우에는 CuO 또는 $Cu_{2}O$와 같은 Cu 산화물은$TiO_{2}$에 비해서 열역학적으로 불안정하기 때문에 이러한 화학적 효과를 기대할 수 없으며, 따라서 충진처리 효과가 거의 없는 것으로 이해된다.