• Analytical Science and Technology
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• v.5 no.1
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• pp.135-142
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• 1992

Indium tin oxide(ITO) films coated on the window glass selectively transmit the solar energy and infrared. We call this system passive solar collectors. Selectively absorbing properties of sol gel dip coated ITO films were characterized by UV-VIS-NIR spectroscopy. The effects of heat treating temperature, time, atmosphere, substrate and barrier layers are concerned. Indium tin oxide films heat-treated at $500^{\circ}C$ in a reducing atmosphere show intrinsic properties. Efficiency of solar energy transmittance was enhanced by coating of $SiO_2-ZrO_2$ as an alkali ion barrier layer. Energy was saved by the double layers of $SiO_2-ZrO_2$ and ITO since solar energy is transmitted and heat generated inside(${\lambda}$ > 2700nm) is reflected.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.399-402
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• 1998

Electroluminescent(EL) devices based on organic thin films have attracted lots of interests in large-area light-emitting display. One of the problems of such device is a lifetime, where a degradation of the cell is possibly due to an organic layers thickness, morphology and interface with electrode. In this study, light-omitting organic electroluminescent devices were fabricated using Alq$_3$(8-hydroxyquinolinate aluminum) and TPD(N,N'-diphenyl-N,N'-bis(3-methylphenyl(1-1\`-biphenyl]-4,4'-diamine). Where Alq$_3$ is an electron-transport and emissive layer, TPD is a hole-transport layer. The cell structure is ITO/TPD/Alq$_3$/Al and the cell is fabricated by vacuum evaporation method. In a measurement of current-voltage characteristics, we obtained a turn-on voltage at about 9 V. We also investigated stability of the devices using buffer layer with blend of PEI (Poly ether imide) and TPD by varying mot ratios between ITO and Alq$_3$. In current-voltage characteristics measurement, we obtained the turn-on voltage at about 6 V and observed an anomalous behavior at 3∼4 V. And we used other buffer layer of PEDT(3,4-pyrazino-3',4'-ethylenedithio-2,2',5,5'-tetrathiafulvalenium) with ITO/PEDT/TPD/Alq$_3$Al structure. We observed a surface morphology by AFM(Atomic Force Microscopy), UV/visible absorption spectrum, and PL(Photoluminescence) spectrum. We obtained the UV/visible absorption peak at 358nm in TPD and at 359nm in Alq$_3$, and the PL peaks at 410nm in TPD and at 510nm in Alq$_3$. We also studied EL spectrum in the cell structure of ITO/(TPD+PEI)/Alq$_3$/Al.

• Journal of the Korean institute of surface engineering
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• v.55 no.6
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• pp.353-362
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• 2022

Recently, transmittance of photomasks for ultra-violet (UV) region is getting more important, as the light source wavelength of an exposure process is shortened due to the demand for technologies about high integration and miniaturization of devices. Meanwhile, such problems can occur as damages or the reduction of yield of photomask as electrostatic damage (ESD) occurs in the weak parts due to the accumulation of static electricity and the electric charge on chromium metal layers which are light shielding layers, caused by the repeated contacts and the peeling off between the photomask and the substrate during the exposure process. Accordingly, there have been studies to improve transmittance and antistatic performance through various functional coatings on the photomask surface. In the present study, we manufactured antireflection films of Nb₂O₅, | SiO₂ structure and antistatic films of ITO designed on 100 × 100 × 3 mmt sodalime glass by DC magnetron sputtering system so that photomask can maintain high transmittance at I-line (365 nm). ITO thin film deposited using In/Sn (10 wt.%) on sodalime glass was optimized to be 10 nm-thick, 3.0 × 103 𝛺/☐ sheet resistance, and about 80% transmittance, which was relatively low transmittance because of the absorption properties of ITO thin film. High average transmittance of 91.45% was obtained from a double side antireflection and antistatic thin films structure of Nb₂O₅ 64 nm | SiO₂ 41 nm | sodalime glass | ITO 10 nm | Nb₂O₅ 64 nm | SiO₂ 41 nm.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1096_1097
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• 2009

Aluminium doped zinc oxide(ZnO:Al) thin film, which is mainly used as a transparent conducting electrode in electronic devices, has many advantages compared with conventional indium tin oxide(ITO). In this paper in order to investigate the possible application of ZnO:Al thin films as a transparent conducting electrode for flexible film-typed dye sensitized solar cell (FT-DSCs), ZnO:Al and ITO thin films were prepared on the polyethylene terephthalate (PET) substrate by r. f. magnetron sputtering method. Specially one-inched FT-DSCs using either a ZnO:Al or ITO electrode were also fabricated separately under the same manufacturing conditions. Some properties of both the FT-DSCs with ZnO:Al and ITO transparent electrodes, such as conversion efficiency, fill factor, and photocurrent were measured and compared with each other. The results showed that by doping the ZnO target with 2 wt% of $Al_2O_3$, the film deposited at discharge power of 200W resulted in the minimum resistivity of $2.2\times10^{-3}\Omega/cm$ and at ransmittance of 91.7%, which are comparable with those of commercially available ITO. Two types of FT-DSCs showed nearly the same tendency of I-V characteristics and the same value of conversion efficiencies. Efficiency of FT-DSCs using ZnO:Al electrode was around 2.6% and that of fabricated FT-DSCs using ITO was 2.5%. This means that ZnO:Al thin film can be used in FT-DSCs as a transparent conducting layer.

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.3
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• pp.43-48
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• 2001

The stability and efficiency of organic light emitting devices are the most critical problems to be solved. The devices based on tris-8-(hydroxyquinoline) aluminum ($Alq_3$) and N,N-diphenyl-N,N-bis(3-methylphenyl)-1, 1-biphenyl-4,4-diamine (TPD) were used to study the effects of buffer layers on their characteristics. We have investigated the characteristic effects of CuPc (copper phthalocyanine) and pentacene buffer layers on the device characteristics, the (5${\sim}$20 nm thick) CuPc layers and the (10${\sim}$20 nm thick) pentacene layers were deposited. Efficiency was slightly improved and the turn-on voltages of the devices with the buffer layers were observed to have lower values than those of the devices without the buffer layers. It is believed that this result is attributed to the improvement of hole injection capability through the buffer layers into hole transport layer (HTL). We have also studied the atomic force microscopic images of the TPD layers deposited on the buffer layer and the bare ITO.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.506-508
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• 2008

In this work, we used impedance spectroscopy analysis to determine the effect of the $HfO_X$ treatment on the surface of ITO and to model the equivalent circuit for OLEDs. Devices with an ITO/Organic material/Al structure can be modeled as resistances and capacitances arranged in parallel or in series. The number of elements depends on the composition of the structure, essentially the number of layers, and the contacts.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.215-215
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• 2014

Red color light emitting diodes (LEDs) were fabricated using CdSe/CdZnS quantum dots (QDs). During the device fabrication process, oxygen plasma treatment on the ITO surface was performed to improve the interfacial contact between ITO anode and the hole injection layer. CdSe/CdZnS quantum dots were cross-linked to remove their surrounded organic surfactants. The device shows red emission at 622 nm, which is consistent with the dimension of the QDs (band gap=1.99 eV). The luminance shows 6026% improvement compared with that of LEDs fabricated without oxygen plasma treatment and quantum dots cross-linking process. This approach would be useful for the fabrication of high-performance QLEDs with ITO electrode and PEDOT:PSS hole injection layers.

• Applied Science and Convergence Technology
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• v.26 no.4
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• pp.91-94
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• 2017

AThe effect of localized surface plasmon on silicon substrates was studied using silver nanoparticles. The nanoparticles were formed by self-arrangement through the surface energy using rapid thermal annealing (RTA) technique after the thin nanolayer of silver was deposited by thermal evaporation. By the theoretical calculation based on Mie scattering and dielectric function of air, indium tin oxide (ITO), and silver, the strong peak of scattering cross section of silver nanoparticles was found at 358 nm for air, and 460 nm for ITO, respectively. Accordingly, the strong suppression of reflectance under the condition of induced light of $30^{\circ}$ occurred at the specific wavelength which is almost in accordance with peak of scattering cross section. When the external quantum efficiency was measured using silicon solar cells with silver nanoparticles, there was small enhancement peak near the 460 nm wavelength in which the light was resonated between silver nanoparticles and ITO.

• Korean Journal of Materials Research
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• v.23 no.3
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• pp.194-198
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• 2013

In this paper, we studied a p-type reflector based on indium tin oxide (ITO) for vertical-type ultraviolet light-emitting diodes (UV LEDs). We investigated the reflectance properties with different deposition methods. An ITO layer with a thickness of 50 nm was deposited by two different methods, sputtering and e-beam evaporation. From the measurement of the optical reflection, we obtained 70% reflectance at a wavelength of 382 nm by means of sputtering, while only 30% reflectance resulted when using the e-beam evaporation method. Also, the light output power of a $1mm{\times}1mm$ vertical chip created with the sputtering method recorded a twofold increase over a chip created with e-beam evaporation method. From the measurement of the root mean square (RMS), we obtained a RMS value 1.3 nm for the ITO layer using the sputtering method, while this value was 5.6 nm for the ITO layer when using the e-beam evaporation method. These decreases in the reflectance and light output power when using the e-beam evaporation method are thought to stem from the rough surface morphology of the ITO layer, which leads to diffused reflection and the absorption of light. However, the turn-on voltage and operation voltage of the two samples showed identical results of 2.42 V and 3.5 V, respectively. Given these results, we conclude that the two ITO layers created by different deposition methods showed no differences in the electric properties of the ohmic contact and series resistance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.177-179
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• 2009

In order to investigate the possible application of ZnO films as a transparent conducting oxide (TCO) electrode, ZnO:Al films were prepared by RF magnetron sputtering method. The effects of surface treatment and doping concentration on the structural and electrical properties of ZnO films were mainly studied experimentally. Five-inch PDP cells using either a ZnO:Al or indium tin oxide (ITO) electrode were also fabricated separately under the same manufacturing conditions. The luminous properties of both the transparent conducting oxide electrode were measured and compared with each other. By doping the ZnO target with 2 wt% of Al2O3, the film deposited at a chemical surface treatment resulted in the minimum resistivity of 8.5 _ 10_4 U-cm and a transmittance of 91.7%. And DBD surface treatment resulted in the minimum resistivity of 8.5 _ 10_4 U-cm and a transmittance of 91.7%. Although the luminance and luminous efficiency of the transparent conducting oxide electrode using ZnO:AI are lower than those of the cell with the ITO electrode by about 10%, these values are sufficient enough to be considered for the normal operation of TCO.