• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.11a
• /
• pp.106-106
• /
• 2009

Al-doped ZnO (AZO) thin films were grown on glass substrates by co-sputtering at room temperature. We made ZnO and Al target and ZnO:Al film is deposited with sputter which has two RF gun source. The Al content was controlled by varying Al RF power and effect of Al contents on the properties of ZnO:Al film was investigated. Crystallinity and orientation of the ZnO:Al films were investigated by X-ray diffraction (XRD), surface morphology of the ZnO:Al films was observed by atomic force microscope. Electrical properties of the ZnO:Al films were measured at room temperature by van der Pauw method and hall measurement. Optrical properties of ZnO:Al films were measured by UV-vis-NIR spectrometer.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.400.2-400.2
• /
• 2016

Dye-sensitized solar cells (DSSCs) have been widely investigated as a next generation solar cell because of their simple structure and low manufacturing cost. To realize a commercially competitive technology of DSSCs, it is imperative to employ a technique to prepare nanocrystlline thin film on the flexible organic substrate, aiming at increasing the flexibility and reducing the weight as well as the overall device thickness of DSSCs. The key operation of glass-to-plastic substrates conversion is to prepare mesoporous TiO2 thin film at low temperature with a high surface area for dye adsorption and a high degree of crystallinity for fast transport of electrons. However, the electron transport in the TiO2 film synthesized at low temperature is very poor. So, in this study, TiO2 films synthesized at high temperature were transferred on the selective substrate. We fabricated DSSCs at low temperature using this method. So, we confirmed that the performance of DSSCs using TiO2 films synthesized at high temperature was improved.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.53 no.10
• /
• pp.505-509
• /
• 2004

The (Sr/sub 0.9/Ca/sub 0.1/)TiO₃(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/SiO₂/Si) using RF sputtering method at various substrate temperature. The optimum conditions of RF power and Ar/O₂ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin film was about 18.75[Å/min]. The crystallinity of SCT thin films were increased with increase of substrate temperature in the temperature range of 100～500[℃]. The dielectric constant of SCT thin films were increased with the increase of substrate temperature, and changed almost linearly in temperature ranges of -80～+90[℃]. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the substrate temperature increases.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.99-99
• /
• 2003

We have investigated the properties of poly (vinyl alcohol)-film obtained by casting from the solution PVA/electrolytes (NaCl, KCl, MgCl$_2$, CaCl$_2$)/water systems at room temperature. The removed electrolytes films have got high crystallinity as well as high draw ratio. The removed electrolytes films had layer-structure while a film without electrolytes didn't have it. A relation between draw ratio and thickness or number of layers, were recognized.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.4
• /
• pp.538-540
• /
• 2009

The SBN thin films were deposited at substrate temperature of 300[$^{\circ}C$] on Pt-coated electrode (Pt/Ti/$SiO_2$/Si(100)) using RF sputtering method. The grain and crystallinity of SBN thin films were increased with the increase of annealing temperature. The dielectric constant(150) of SBN thin film was obtained by annealing temperature above 750[$^{\circ}C$]. The voltage dependence of dielectric loss showed a value within 0.01 in voltage ranges of -5~+5[V]. The capacitance characteristics showed a stable value of about 0.7[${\mu}F/cm^2$].

• Journal of the Semiconductor & Display Technology
• /
• v.7 no.3
• /
• pp.51-54
• /
• 2008

In this study, we investigated variations in undoped ZnO thin film properties with working pressure, $O_2$/Ar ratio, and annealing ambient. Higher vacuum pressure during deposition was observed to bring about slower growth rate resulting in samples with better crystallinity as well as hole generation efficiency through formation of shallower oxygen interstitial. Given that $O_2$/Ar ratio is greater than unity, O provided from the ambient to ZnO during annealing was found to preferably situate at interstitial sites. When He was used for the second annealing, significant changes were not observed. On the other hand, O ambient caused increased density of oxygen interstitial, thereby making the film more intrinsic-like high resistivity ZnO.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1998.06a
• /
• pp.71-74
• /
• 1998

$Er^{3+}$ doped $NdF_{3}$ single crystalline thin films with smooth, microcrack-free, and high-crystalline quality were grown on $CaF_{2}(111)$ substrate at $500^{\circ}C$by molecular beem epitaxy(MBE). The relation-ship between subcell and supercell showing the reconstructed $3^{1/2} \times 3^{1/2}$ structure was studied by reflection high-energy electron diffraction(RHEED) investigation. The film surface and the growth mode were examined in studied by RHEED patterns and atomic force microscope(AFM) images ex situ. The crystallinity of film and the lattice mismatch between $NdF_{3}Er}^{3+}(0002)$ film and $CaF_{2}(111)$ substrate depending in the $Er^{3+}$ concentration were investigated by X-ray rocking curve analysis.

• Journal of the Korean Vacuum Society
• /
• v.5 no.1
• /
• pp.77-84
• /
• 1996

Silicon deposition by Penning discharge was carried out using a mixture of 5% $SiH_4/H_2$ and Ar gas, and the effects of the deposition conditions(gas mixing raito, substrate temperature. discharge power etc.) on the growth rate, crystallinity and morphology of the films deposited were investigated. The magnetic field(800 G) confined the plasma in the region between the two cathodes and enhanced the discharge current by a factor of a few hundreds below 1 mTorr. The magnetic field-enhanced plasma density resulted in a very large deposition rate of about 300 $\AA$/min at $SiH_4$ flow rate of 0.7 sccm and the substrate temperature of $800^{\circ}C$. Characterization of the films by Raman spectroscopy, X-ray diffraction, and scanning electron microscopy revealed that an epitaxial film with a smooth surface grows above 80$0^{\circ}C$, an amorphous film below $400^{\circ}C$, and a rough polycrystalline film at intermediate temperatures.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.688-691
• /
• 1997

Good quality superconducting $YBa_2Cu_30_{7-{\delta}}$(YBCO) thin films were grown on Hastelloy (Ni-Cr-Mo alloys) with yttria-stabilized zirconia(YSZ) buffer layers by in situ pulsed laser deposition in a multi-target processing chamber. Generally, Hastelloy exhibits excellent resistance to corrosion, fatigue, thermal shock, impact, and erosion. However, it is difficult to make films on flexible metallic substrates due to interdiffusion problems between metallic substrates and superconducting overlayers. To overcome this difficulty, it is necessary to use YSZ buffer layer since it will not only limit the interdiffusion process but also minimize the surface microcrack formation due to smaller mismatch between the film and the substrate. In order to enhance the crystallinity of YBCO films on metallic substrates, YSZ buffer layers were grown at various temperatures different from the deposition temperature of YBCO films. On YSZ buffer layer grown at higher temperature than that for depositing YBCO film, the YBCO thin film was found to be textured with c-axis orientation by x-ray diffraction and had a zero-resistance critical temperature of about 85K.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.112-112
• /
• 2010

Zinc Oxide (ZnO) thin-films were deposited according to the magnetron sputtering method. The deposited ZnO films were annealed with RTA equipment at various annealing temperatures in an vacuum ambient. The influence of the annealing temperature on the structural, electrical, and optical properties of the ZnO films was experimentally investigated, and the effect of conductivity of the ZnO active layer on the device performance of the oxide-TFT was tested. As a result, an increase of the annealing temperature was attributed to improvements of crystallinity in ZnO films. The grain size was found to lead to an increase of conductivity in the ZnO films. Fabricated ZnO TFTs with annealed ZnO active layer provided good performance in the TFT devices. Consequently, the performance of the TFT was determined by the conductivity of the ZnO film, which was related to the structural properties of the ZnO film.