• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.267-267
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• 2010

염료 감응형 태양전지는 일반적으로 투명 전극 기판, 염료가 흡착된 $TiO_2$, 전해질, Pt가 코팅된 투명 전극 기판으로 구성된다. 이 중 투명 전극 기판은 전체 재료비 중 60% 이상을 차지하여 이를 대체하는 새로운 구조에 대한 연구가 활발히 진행 중이다. 본 논문에서는 투명 전극 기판을 사용하지 않는 염료 감응형 태양전지를 연구하였다. $TiO_2$ 위에 e-beam 증착을 이용하여 다공성의 Ti 전극을 형성하였다. Ti 전극의 다공성은 SEM 분석 및 염료 흡착을 통해 확인하였다. Ti 전극의 두께가 증가함에 따라 표면저항은 감소하였으며, 태양전지의 효율은 증가하는 경향을 보였다. 또한 Ti 전극의 표면저항이 투명 전극 기판의 표면저항과 동등 수준일 경우 효율 또한 동등 수준을 나타내었다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.13-17
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• 2005

The Pb(Zr/sub 0.52/Ti/sub 0.48/)O₃/(Ba/sub 0.6/Sr/sub 0.4/)TiO₃[PZT/BST] heterolayered thin films were deposited on Pt/Ti/SiO₂/Si substrates by using the RF sputtering method with different RF power. The PZT/BST heterolayered thin films had the tetragonal structure of the PZT phase and BST phase. Increasing the RF power. the intensity of the PZT (100), (110) peaks and BST (111) peaks were decreased and the intensity of the BST (100), (110) peaks were increased. The thickness ratio of the top layered BST thin film and the bottom layered PZT thin film was 2 to1. The atomic concentration of the Ba, Sr, Pb. Zr, Ti atoms were constant in the PZT thin films and BST thin films, respectively. The Pt atom was diffused to the PZT region in the PZT/BST heterolayered thin films deposited at condition of 60[W] RF power. Increasing the frequency, dielectric constant and loss of the PZT/BST heterolayered thin films were decreased. The dielectric constant and loss of the PZT/BST heterolayered thin films deposited with RF power of 90[W] were 406 and 3%, respectively.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.132-137
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• 1996

Pb(Zr$_{x}$Ti$_{1-x}$ )O$_{3}$ solutions prepared by sol-gel processing with different Zr/Ti ratio were coated on Pt/SiO$_{2}$/Si substrates using spin coating method. Coated films were annealed by rapid thermal annealing at 650.deg. C for 20sec to fabricate Pb(Zr, Ti)O$_{3}$ ferroelectric thin films. Electrical properties of the films such as dielectric constant and loss, ferroelectric hysteresis, fatigue, switching time, and leakage current were measured. Hysteresis of the films with different Zr/Ti ratio yield Pr ranging 10-21.mu.C/cm$^{2}$, E$_{c}$ ranging 37.5-137.5kV/cm. Hysteresis curve was changed from square-type to slim type according to increasing Zr contents. Switching time was faster than 180ns, and leakage current was about 20.mu.A/cm$^{2}$. The film underwent above 10$^{8}$ cycles of reversed polarization showed fatigue with increased coercive field and decreased remnant polarization.tion.

• Journal of the Korean Ceramic Society
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• v.34 no.6
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• pp.620-628
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• 1997

The possibility of the existence of a field-induced micro-macrodomain switching was proposed and examined using 9 mol % PbZrO3-doped 0.6Pb(Ni1/3Nb2/3)O3-PbTiO3 (PNN-PT) systems having rhombohedral symmetry at room temperature. the thermally depoled (freshly prepard) specimens prepared from the rhombohedral side of the system exhibited a relaxor behavior for the whole range of temperature examined (for T

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.4013-4018
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• 2014

A 0.45 $cm^2$ DSSC device with a glass/FTO/blocking layer/$TiO_2$/N719(dye)/electrolyte/50 nm-Pt/50 nm-Au/FTO/glass was prepared to examine the stability of the Au/Pt bilayered counter electrode (CE) with electrolyte and the energy conversion efficiency (ECE) of dye-sensitized solar cells (DSSCs). For comparison, a 100 nm-thick Pt only CE DSSC was also prepared using the same method. The photovoltaic properties, such as the short circuit current density ($J_{sc}$), open circuit voltage ($V_{oc}$), fill factor (FF), and ECE, were checked using a solar simulator and potentiostat with time after assembling the DSSC. The microstructure of the Au/Pt bilayer was examined by optical microscopy after 0~25 minutes. The ECE of the Pt only CE-employed DSSC was 4.60 %, which did not show time dependence. On the other hand, for the Au/Pt CE DSSC, the ECEs after 0, 5 and 15 minutes were 5.28 %, 3.64 % and 2.09 %, respectively. The corrosion areas of the Au/Pt CE determined by optical microscopy after 0, 5, and 25 minutes were 0, 21.92 and 34.06 %. These results confirmed that the ECE and catalytic activity of Au/Pt CE decreased drastically with time. Therefore, a Au/Pt CE-employed DSSC may be superior to the Pt only CE-employed one immediately after integration of the device, but it would degrade drastically with time.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1324_1325
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• 2009

The heterolayered $BaTiO_3/(Bi_{0.5}Na_{0.5})TiO_3$ thick films were fabricated by screen printing techniques on alumina substrates electrodes with Pt. We report the improved ferroelectric properties in the heterolayered teteragonal/rhombohedral structure composed of the $BaTiO_3$ and the $(Bi_{0.5}Na_{0.5})TiO_3$ thick films. We investigated the effects of deposition conditions on the structural and electrical properties of the heterolayered BNT/BT thick films. The structural and electrical properties of the heterolayered BNT/BT thick films were studied. All PZT heterolayered thin films show dense and homogeneous structure without the presence of the rosette structure. The dielectric constant, loss and remanent polarization oft heheterolayered BNT/BT thick films were superior to those of single composition $BaTiO_3$ and $(Bi_{1/2}Na_{1/2})TiO_3$, and those values for the heterolayered BNT/BT thick films sintered at $1100^{\circ}C$ were 916, 0.79 and $12.63{\mu}C/cm^2$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.553-558
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• 2003

The A S $r_{0.7}$B $i_{2.6}$T $a_2$ $O_{9}$ (SBT)thin films are deposited on Pt-coated electrode(Pt/$TiO_2$/$SiO_2$/Si) using a RF magnetron sputtering method. The electrical properties of SBT capacitors with top electrodes were studied. In the XRD pattern, the SBT thin films in all annealing temperatures had (105) orientation. In the SEM images, Bi-layered perovskite phase was crystallized at 75$0^{\circ}C$ and grains largely grew in oxygen annealing atmosphere. The electrical properties of SBT capacitor with top electrodes represent a favorable properties in Pt electrode. The maximum remanent polarization and the coercive electric field with Pt electrode are 12.40C/$\textrm{cm}^2$ and 30kV/cm, respectively. The dielectric constant and leakage current density with Pt electrode is 340 and 6.8110$^{-10}$ A/$\textrm{cm}^2$, respectively.y.y.

• Journal of the Korean Vacuum Society
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• v.19 no.1
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• pp.52-57
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• 2010

$BiFeO_3/Pb(Zr_{0.52}Ti_{0.48})O_3$(BFO/PZT) multilayer thin films have been prepared on a Pt/Ti/$SiO_2$/Si(100) substrate by chemical solution deposition. BFO single layer, BFO/PZT bilayer and multilayer thin films were studied for comparison. X-ray diffraction analysis showed that the crystal structure of all films was multi-orientated perovskite phase without amorphous and impurity phase. The leakage current density at 500 kV/cm was reduced by approximately four and five orders of magnitude by bilayer and multilayer structure films, compared with BFO single layer film. The low leakage current density leads to saturated P-E hysteresis loops of bilayer and multilayer films. In BFO/PZT multlayer film, saturated remanent polarization of $44.3{\mu}C/cm^2$ was obtained at room temperature at 1 kHz with the coercive field($2E_c$) of 681.4 kV/cm.

• Transactions on Electrical and Electronic Materials
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• v.11 no.4
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• pp.182-185
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• 2010

$Pb_{0.99}[(Zr_{0.6}Sn_{0.4})_{0.9}Ti_{0.1}]_{0.98}Nb_{0.02}O_3$ (PNZST) thin films were deposited by radio frequency magnetron sputtering on a $(La_{0.5}Sr_{0.5})CoO_3$ (LSCO)/Pt/Ti/$SiO_2$/Si substrate using a PNZST target with an excess PbO of 10 mole%. The thin films deposited at the substrate temperature of $500^{\circ}C$ crystallized to a perovskite phase after rapid thermal annealing (RTA). The thin films, which annealed at $650^{\circ}C$ for 10 seconds in air, exhibited good crystal structures and ferroelectric properties. The remanent polarization and coercive field of the fabricated PNZST capacitor were approximately $20uC/cm^2$ and 50 kV/cm, respectively. The reduction of the polarization after $2.2\;{\times}\;10^9$ switching cycles was less than 10%.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.121-123
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• 2002

졸-겔법(Sol-Gel Method)으로 강유전체 Bi/sub 3.3/La/sub 0.7/Ti/sub 3/O/sub 12/(BLT) 박막을 Pt/Ti/SiO₂/Si 기판위에 스핀 코팅하여 Metal-Ferroelectric-Metal(MFM 구조를 형성하였다. As-coated BLT 박막은 650℃ 이상에서 결정화되었으며, 전형적인 Bi층상의 페롭스카이트 결정구조를 나타내었다. 또한 열처리 온도를 증가시킴에 따라 결정성이 향상되었다. 3V 전압에서 650℃로 열처리된 박막의 경우 누설전류가 약 2.25×10/sup -8/A/㎠ 정도를 보였다. 650℃에서 열처리된 BLT박막은 5V의 인가 전압에서 잔류분극 2Pr(±(P/sup */-P/sup A/)) 값은 약 29.5μC/㎠을 나타내었으며, 1.5×10/sup 10/ 스위칭 cycles까지 분극 스위칭을 반복한 후에도 거의 잔류 분극의 변화가 없었다.