• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1136-1139
• /
• 2009

Recently, various Ni doping systems and thermal annealing systems have been developed for fabrication of polycrystalline silicon film using SGS (super grain silicon) for medium and largesize AMOLED panels. In this study, we compare the potential of Ni doping systems including ALD (atomic layer deposition), AMD (atmospheric metal deposition), in-line sputter, and crystallization annealing systems including batch type furnace, inline furnace, and RTA (rapid thermal annealing) developed for the SGS method. Additional requirements for those systems to be used for mass production of large AMOLED TVs are suggested based on evaluation results for both poly-Si films and TFT backplanes.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.418.1-418.1
• /
• 2016

Atomic layer deposition (ALD)를 이용하여 증착된 aluminum oxide ($Al_2O_3$)는 우수한 패시베이션 특성을 가지고 있다. $Al_2O_3$ 박막은 많은 수소를 가지고 있기 때문에 화학적 패시베이션에 의한 실리콘 표면을 패시베이션 할 수 있다. 또한 $Al_2O_3$는 강한 고정전하를 가져 전계 효과 패시베이션을 할 수 있다. 따라서 $Al_2O_3$ 박막을 태양전지에 적용할 경우 높은 효율을 기대할 수 있다. 실리콘 태양전지를 제작하기 위해 소성공정(> $800^{\circ}C$)은 필수이다. $Al_2O_3$ 박막은 많은 수소를 가지고 있기 때문에 소성공정시 수소가스를 방출하여 $Al_2O_3$ 박막에 블리스터를 형성시킨다. 이 블리스터는 $Al_2O_3/Si$ 계면에서 발생하여 패시베이션 특성을 감소시킨다. 블리스터를 억제하기 위해 수소의 양을 조절할 필요가 있다. 이 실험에서는 plasma-assisted atomic layer deposition (PAALD)으로 $Al_2O_3$를 증착하였다. PAALD의 RF power를 200 W부터 800 W까지 조절하여 $Al_2O_3$ 막에 포함되는 OH의 농도를 조절하였다. $Al_2O_3$ 박막에 포함되는 OH 농도는 X-ray Photoelectron Spectroscopy (XPS)를 이용하여 분석하였다. 열처리공정 후, 화학적 패시베이션에 의한 유효 반송자 수명 (${\tau}_{eff}$) 향상이 나타났다 소성공정 후 블리스터가 형성되지 않는 조건에서 화학적 패시베이션과 전계 효과 패시베이션에 의해 ${\tau}_{eff}$가 증가하였다. 블리스터가 형성되었을 때 기존 논문들과 같이 패시베이션 특성이 감소하였다. 패시베이션 특성의 감소는 블리스터에 의한 화학적 패시베이션의 감소 때문이며 전계 효과 패시베이션은 오히려 증가하였다. 이를 통해 고온에서 열안정성을 갖는 $Al_2O_3$ 박막을 만들었으며 블리스터가 형성되지 않았고 패시베이션 특성이 증가하였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.165-165
• /
• 2013

Nickel oxide was deposited on mesoporous silica by atomic layer deposition (ALD) consisting of sequential exposures to Ni(cp)2 and $H_2O$. NiO/silica samples were characterized by inductively coupled plasma-mass spectroscopy (ICP-MS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), etc. The flow-type reactor was used to measure activity of NiO/silica catalyst for catalytic combustion of toluene. The activity of NiO/silica catalyst was evaluated in terms of toluene removal efficiency and selectivity to $CO_2$ and compared with those of bare nickel oxide nanoparticles. In order to investigate influence of reaction temperature on combustion aspect, the catalytic combustion experiments were carried out at various temperatures. We show that both bare and supported NiO can be efficient catalysts for total oxidation of toluene at a temperature as low as $250^{\circ}C$.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.425-425
• /
• 2011

The photocatalytic decomposition of toluene gas was investigated with $TiO_2$ on nano-diamond powder (NDP) under UV irradiation. Atomic layer deposition (ALD) was used for the growth of $TiO_2$ on the NDP. The structure and surface properties of catalysts were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). The photocatalytic activity for the toluene decomposition was evaluated by measuring the concentration change of toluene and $CO_2$ gas with gas chromatography (GC)-flame ionization detector (FID) system. The photocatalytic activities of $TiO_2$/NDP catalysts were compared with that of P-25. The rate of initial photocatalytic decomposition of toluene for the $TiO_2$/NDP catalysts was relatively lower when compared to P-25. The photocatalytic activity of P-25 was rapidly decreased with time, whereas, the deactivation of $TiO_2$/NDP catalysts was less pronounced. Therefore, as the reaction time increased, the photocatalytic activity of $TiO_2$/NDP catalysts became higher than that of P-25. The intermediates such as benzaldehyde or benzoic acid, etc were more easily adhered to the active site on the P-25 surface during reaction, resulting in easier deactivation of P-25. These results could be confirmed using FT-IR spectroscopy. We suggest that the NDP used as substrate can reduce the deactivation of $TiO_2$ on the surface.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.167.2-167.2
• /
• 2014

In this work, ZnO shell on mesoporous $SiO_2$ ($ZnO/SiO_2$) was prepared by atomic layer deposition (ALD). Diethylzinc (DEZ) and $H_2O$ were used as precursor of ZnO shell. $ZnO/SiO_2$ sample was characterized by X-ray diffraction (XRD), N2 sorption isotherms, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). $ZnO/SiO_2$ showed higher adsorption capacity of MB than that of bare mesoporous $SiO_2$ and the adsorption capacities of $ZnO/SiO_2$ could be regenerated by UV exposure through the photocatalytic degradation of the adsorbed MB. This system could be used for removing organic dye from water by adsorption and reused after saturation of adsorption due to its photocatalytic regeneration.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.443-443
• /
• 2011

Atomic layer deposition (ALD) was used to deposit $TiO_2$ on Ni particles, and changes in the catalytic activity of Ni for $CO_2$ reforming of methane (CRM) were studied. In the presence of $TiO_2$ islands on Ni surfaces, the onset temperature of the CRM reaction was lower than that of bare Ni. During the CRM reaction, carbon was deposited on the surface, reducing the catalytic activity of the surface, but $TiO_2$ was able to remove the carbon deposits from the surface. When the Ni surface was completely covered with $TiO_2$, catalytic activity disappeared, indicating that tuning of $TiO_2$ coverage on Ni is important for maximizing the activity of the CRM reaction.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.91-91
• /
• 2012

We aim in synthesizing various functional thin films thinner than ~ 10 nm for environmental applications and photovoltaic devices. Atomic layer deposition is used for synthesizing inorganic thin films with a precise control of the film thickness. Several examples about application of our thin films for removing volatile organic compounds (VOC) will be highlighted, which are summarized in the below. 1) $TiO_2$ thin films prepared by ALD at low temperature ($<100^{\circ}C$) show high adsorption capacity for toluene. In combination with nanostructured templates, $TiO_2$ thin films can be used as building-block of high-performing VOC filter. 2) $TiO_2$ thin films on carbon fibers and nanodiamonds annealed at high temperatures are active for photocatalytic oxidation of VOCs, i.e. photocatalytic filter can be created by atomic layer deposition. 3) NiO can catalyze oxidation of toluene to $CO_2$ and $H_2O$ at $<300^{\circ}C$. $TiO_2$ thin films on NiO can reduce poisoning of NiO surfaces by reaction intermediates below $200^{\circ}C$. We also fabricated inverted organic solar cell based on ZnO electron collecting layers on ITO. $TiO_2$ thin films with a mean diameter less than 3 nm on ZnO can enhance photovoltaic performance by reducing electron-hole recombination on ZnO surfaces.

• Bulletin of the Korean Chemical Society
• /
• 제33권7호
• /
• pp.2200-2206
• /
• 2012

One-dimensional $TiO_2$ array grown on optically transparent electrode holds a promise as a photoelectrode for photoelectrochemical water splitting; however, its crystal structure is rutile, imposing constraints on the potent use of this nanostructure. To address this issue, a heterojunction with type-II band alignment was fabricated using atomic layer deposition (ALD) technique. One-dimensional core/shell structured $TiO_2$/ZnO heterojunction was superior to $TiO_2$ in the photoelectrochemical water splitting because of better charge separation and more favorable Fermi level. The heterojunction also possesses better light scattering property, which turned out to be beneficial even for improving the photoelectrochemical performance of semiconductor-sensitized solar cell.

• 한국세라믹학회지
• /
• 제56권3호
• /
• pp.302-307
• /
• 2019

The intrinsic oxygen-vacancy defects in ZnO have prevented the preparation of p-type ZnO with high carrier concentration. Therefore, in this work, the effect of the concentration of H₂O₂ (used as an oxygen source) on the oxygen-vacancy concentration in ZnO prepared by atomic layer deposition was investigated. The results indicated that the oxygen-vacancy concentration in the ZnO film decreased by the oxygen-rich growth conditions when using H₂O₂ as the oxygen precursor instead of a conventional oxygen source such as H₂O. The suppression of oxygen vacancies decreased the carrier concentration and increased the resistivity. Moreover, the growth orientation changed to the (002) plane, from the combined (100) and (002) planes, with the increase in H₂O₂ concentration. The passivation of oxygen-vacancy defects in ZnO can contribute to the preparation of p-type ZnO.

• 전기학회논문지
• /
• 제63권10호
• /
• pp.1412-1416
• /
• 2014

We report thin-film organic moisture barriers based on polystyrene(PS) laminates deposition by PECVD for an encapsulation of OLEDs. The organic polystyrene thin-film has the benzene ring structure and high hydrophobic characteristics and it was polymerized by PECVD in dry process. Life time properties of Ca test were obtained 32 minutes at the RF 100W process conditions. From the AFM test, the roughness of multi-layer thin-film was more excellent rather than that of a single-layer thin-film. In addition, 5 layers of the multi-layer film properties were obtained 45 minutes. So that the optical and electrical properties were not affected with these plasma polymerized organic thin-film encapsulation. For life time improvement, the inorganic $Al_2O_3$ thin-film were deposited 5nm using ALD atomic layer deposition. The WVTR(Water Vaper Transmission Rate) value of hybrid thin-film encapsulation in the optimum process conditions was resulted by less than $10-3g/m^2/day$. From the results of experiment, plasma polymerized hybrid encapsulation was suggested as the flexible display applications.