• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.85-90
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• 2017

The $TiCl_4$ as a blocking material is adsorbed in the mesoporous $TiO_2$ electron transfer layer(ETL) of the Perovskite solar cell to prevent the direct contact between the FTO electrode and the photoactive layer(AL), and facilitate the movement of the electrons between $TiO_2:TiCl_4$ ETL and Perovskite AL to improve the photoelectric conversion efficiency(PCE). The structure of the perovskite solar cell is FTO/$TiO_2:TiCl_4$/Perovskite($CH_3NH_3PbI_3$)/spiro-OMeTAD/Ag. It was investigated that the dipping time of the $TiO_2$ into $TiCl_4$ aqueous solution affects on the photoelectric characteristics of the device. By the dipping for 30 minutes, the PCE of the perovskite solar cell with the $TiO_2:TiCl_4$ ETL was the highest 10.46%, which is 27% higher than the cell with $TiO_2$ ETL. From SEM, EDS, and XRD characterization on the $TiO_2:TiCl_4$ ETL and the perovskite AL, it was measured that the decrease of the porosity of the $TiO_2$ layer, the detection of the Cl component by the $TiCl_4$ adsorption, the cube-type morphology of perovskite AL, and shift of the $PbI_2$ peak of the perovskite AL. From these results, it was confirmed that the $TiO_2:TiCl_4$ ETL and the perovskite AL were formed.

• Journal of the Korean Ceramic Society
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• v.24 no.4
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• pp.397-403
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• 1987

Pb(Zr0.52Ti0.48)O3 powders were prepared by hydrothermal synthesis. Using soluble salts such as Pb(NO3)2, TiCl4 and ZrOCl2$.$8H2O and oxide such as PbO and TiO2 as starting materials, PZT powder was hydrothermally synthesized at the temperature range between 150$^{\circ}C$ and 200$^{\circ}C$. The result showed that reactivity by alkali was decreased in the sequence of Pb(NO3)2, TiCl4, ZrOCl2, PbO, TiO2 and ZrO2. Using the first three soluble salts, PZT powder was synthesiged at 150$^{\circ}C$ for 1hr. In PbO-TiCl4-ZrOCl2 system, PZT powder was synthesized at 150$^{\circ}C$ for 8rs. In Pb(NO3)2-TiO2-ZrOCl2 system, PZT powder was synthesized at 150$^{\circ}C$ for 16hrs, in PbO-TiO2-ZrOCl2 system, the powder was synthesized at 200$^{\circ}C$ for 8hrs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.276-279
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• 2011

This work, the etching characteristics of $Ba_2Ti_9O_{20}$(BTO) thin films were investigated using an inductively coupled plasma (ICP) of $Ar/Cl_2$ gas mixture. The etch rate of BTO thin films as well as the $BTO/SiO_2$ and BTO/PR etch selectivity were measured as functions of $Ar/Cl_2$ mixing ratio (0~100% Ar) at a constants gas pressure (6 mTorr), total gas flow rate (50 sccm), input power (700 W) and bias power (200 W). The etch rate of BTO thin films decreased with increasing Ar fraction. To analyze the etching mechanism an optical emission spectroscopy (OES), double Langmuir probe(DLP) and surface analysis using X-ray photoelectron spectroscopy (XPS) were carried out.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.11
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• pp.18-24
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• 2000

(Ba,Sr)$TiO_3$ thin films have attracted great interest as new dielectric materials of capacitors for ultra-large-scale integrated dynamic random access memories (ULSI-DRAMs) such as 1 Gbit or 4 Gbit. In this study, inductively coupled $BCl_3/Cl_2/Ar$ plasmas was used to etch (Ba,Sr)$TiO_3$ thin films. RF power/dc bias voltage=600 W/-250 V and chamber pressure was 10 mTorr. The $Cl_2/(Cl_2+Ar)$ was fixed at 0.2 the (Ba,Sr)$TiO_3$ thin films were etched adding $BCl_3$. The highest (Ba,Sr)$TiO_3$ etch rate is $480{\AA}/min$ at 10 % $BCl_3$ to $Cl_2/Ar$. The change of Cl, B radical density measured by optical emission spectroscopy(OES) as a function of $BCl_3$ percentage in $Cl_2/Ar$. The highest Cl radical density was shown at the addition of 10% $BCl_3$ to $Cl_2/Ar$. To study on the surface reaction of (Ba, Sr)$TiO_3$ thin films was investigated by XPS analysis. Ion bombardment etching is necessary to break Ba-O bond and to remove $BaCl_2$. There is a little chemical reaction between Sr and Cl, but Sr is removed by physical sputtering. There is a chemical reaction between Ti and Cl, and $TiCl_4$ is removed with ease. The cross-sectional of (Ba,Sr)$TiO_3$ thin film was investigated by scanning electron microscopy (SEM), the etch slope is about 65~70$^{\circ}$.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.208-208
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• 2003

저온균일침전법(HPPLT)으로 제조된 TiO$_2$나노분말은 10$0^{\circ}C$이하의 온도에서 rutile상을 얻을 수 있다. 또한, rutile에서 anatase로의 상변화는 합성시간, 가열속도, 반응온도 그리고 음이온 첨가에 의해 일어난다고 보고되어졌지만, 금속양이온들에 의한 상변화는 알려진 바가 없다. 따라서, 다양한 양이온을 첨가하여 저온균일침전법에서 TiO$_2$의 상변화가 어떻게 일어나는지를 조사하였다. 출발원료인 TIC1$_4$를 사용하여 가수분해하여 0.67M의 TiOCl$_2$을 얻었다. 얻어진 TiOCl$_2$ 수용액에 각각 0.01M의 금속염화물(ZrOCl$_2$, NiCl$_2$, CuCl$_2$, FeCl$_3$, AlCl$_3$ 그리고 NbCl$_{5}$)을 첨가한 후 반응기에 넣고 10$0^{\circ}C$에서 4시간동안 가열하였다 가열한 후 얻어진 침전물에 NaOH 수용액을 이용하여 PH 7-8로 중화한 후 증류수로 Cl$^{-}$이온이 제거될 때까지 충분히 세척하였다. 세척된 침전물을 105$^{\circ}C$에서 24h동안 건조하여 분말을 얻었고, rutile에서 anatase로의 상변화특성을 관찰하기 위하여 XRD, SEM, TEM, ICP 분석을 실시하였다.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1378-1386
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• 1994

The characteristic of calcined BaTiO3 powder and sintered PTC ceramics was investigated varing with calcination temperature and time of BaTiO(C2O4)2.4H2O synthesized from BaCl2.2H2O, TiCl4, oxalic acid and ethanol by oxalic acid method. When the particle size was less than 0.1 ${\mu}{\textrm}{m}$ by controlling calcination temperature and time, the resistance at room temperature was measured very high (above M{{{{ OMEGA }}). However, when the calcined particle sizes ranged from 0.2 to 0.3 ${\mu}{\textrm}{m}$, the resistance was 100 {{{{ OMEGA }} (After sintering, the grain size was 10~30 ${\mu}{\textrm}{m}$ homogeneously with the addition of dopant in sintering, the resistivity, resistance, $\alpha$ value and jumped to were 110{{{{ OMEGA }}.cm, 24$^{\circ}C$/% and 106{{{{ OMEGA }}, respectively.

• Journal of Powder Materials
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• v.24 no.6
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• pp.477-482
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• 2017

Nitrogen-doped titanium dioxide (N-doped $TiO_2$) is attracting continuously increasing attention as a material for environmental photocatalysis. The N-atoms can occupy both interstitial and substitutional positions in the solid, with some evidence of a preference for interstitial sites. In this study, N-doped $TiO_2$ is prepared by the sol-gel method using $NH_4OH$ and $NH_4Cl$ as N ion doping agents, and the physical and photocatalytic properties with changes in the synthesis temperature and amount of agent are analyzed. The photocatalytic activities of the N-doped $TiO_2$ samples are evaluated based on the decomposition of methylene blue (MB) under visible-light irradiation. The addition of 5 wt% $NH_4Cl$ produces the best physical properties. As per the UV-vis analysis results, the N-doped $TiO_2$ exhibits a higher visible-light activity than the undoped $TiO_2$. The wavelength of the N-doped $TiO_2$ shifts to the visible-light region up to 412 nm. In addition, this sample shows MB removal of approximately 81%, with the whiteness increasing to +97 when the synthesis temperature is $600^{\circ}C$. The coloration and phase structure of the N-doped $TiO_2$ are characterized in detail using UV-vis, CIE Lab color parameter measurements, and powder X-ray diffraction (XRD).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.14-19
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• 2010

Partial anodic oxidation of Ti-mesh with a wire diameter of ~200[${\mu}m$] produces self-aligned $TiO_2$ nanotube arrays (~50[${\mu}m$] in length) on Ti-mesh substrate. The electrolyte used for anodic oxidation was an ethylene glycol solution with an addition of 1.5 vol. % $H_2O$ and 0.2 wt. % $NH_4F$. A dye-sensitized solar cell utilizing the photoanode structure of $TiO_2$-nanotube/Ti-mesh was fabricated without a transparent conducting oxide (TCO) layer, in which Ti-mesh replaced the role of TCO. The 1.93[%] photoconversion efficiency was low, which can be attributed to both insufficient dye molecules attachment and limited electrolyte flow to dye molecules. The optimized nanotube diameter and length as well as the $TiCl_4$ treatment can improve cell performance.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.83-85
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• 2008

4성분계 Ti-Si-C-N 코팅막은 $TiCl_4$, $SiH_4$, $CH_4$, Ar, 그리고 $N_2$ 가스 혼합체를 이용하여 RF-PECVD 기법에 의해 Si 와 AISI 304 기판위에 합성하였다. Ti-C-(0.6)-N(0.4) 조성의 코팅막에 Si를 첨가함으로 Ti(C,N) 결정질은 줄어들고, Si3N4 및 SiC 비정질상이 나타났다. Ti-Si(9.2 at.%)-C-N의 조성에서 나노 크기의 nc-Ti(C,N) 결정질을 비정질 a-Si3N4/SiC가 둘러싸고 있는 형태의 나노 복합체를 나타내었다. 경도 24 Gpa의 Ti-C-N 코팅막은 Si를 첨가함으로 Ti-Si(9.2 at.%)-C-N 조성에서 46 Gpa의 최고 경도를 나타내었으며, 마찰계수의 경우에도 Ti-C-N 코팅막에 Si를 첨가함으로 크게 낮아졌다.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.272-276
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• 2005

Food wastewater derived from three-stages methane fermentation system showed high concentrations of sCOD, T-N and $NH_{3}-N$. To treat the organic wastewater, the optimal operating conditions for high efficiency $UV/TiO_{2}$ photocotalytic system have been investigated. In the first process, wastewater was pre-treated with $FeCl_{3}. The optimum pH and concentration for coagulation were 4.0 and 2000 mg/L, respectively. Through this process, 52.6% of $COD_{cr}$ was removed. The second process was $UV/TiO_{2}$ photocatalytic reaction. The optimum conditions for the operation of $UV/TiO_{2}$ photocatalytic system developed in this lab have been studied. In this process, CODcr was removed from 2890 to 184 mg/L and T-N was removed from 2496 to 914 for 24 hours, respectively.