• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.399-400
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• 2007

In this work, we have investigated the characteristics of the phosphorescent OLED and flexible OLED fabricated on IZTO/glass and IZTO/PET anode film grown by magnetron sputtering, respectively. Electrical and optical characteristics of amorphous IZTO/glass anode exhibited similar to commercial ITO anode even though it was deposited at room temperature. In addition, the amorphous IZTO anode showed higher work function than that of the commercial ITO anode after ozone treatment for 10 minutes. Furthermore, a phosphorescent OLED fabricated on amorphous IZTO anode film showed improved current-voltage-luminance characteristics, external quantum efficiency and power efficiency in contrast with phosphorescent OLED fabricated on commercial ITO anode film. This indicates that IZTO anode is promising alternative anode materials for anode in OLEDs and flexible OLEDs.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.77.1-77.1
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.412-413
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• 2007

We report on the electrical, optical, and structural properties of indium zinc tin oxide (IZTO) anode films grown at room temperature on glass substrate. The IZTO anode films grown by a RF magnetron sputtering were investigated as functions of RF power, working pressure, and process time in pure Ar ambient. To investigate electrical, optical and structural properties of IZTO anode films, 4-point probe, Hall measurement, UV/Vis spectrometer, Field Emission Scanning Electron Microscopy (FE-SEM), and X-ray diffraction (XRD) were performed, respectively. A sheet resistance of $13.88\;{\Omega}/{\square}$, average transmittance above 80 % in visible range were obtained from optimized IZTO anode films grown on glass substrate. These results shown the amorphous structure regardless of RF power and working pressure due to low substrate temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.167-167
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• 2010

Indium tin oxide (ITO) has been widely used as transparent conductive oxides (TCOs) for transparent electrodes of various optoelectronic devices, such as liquid crystal displays (LCD) and organic light emitting diodes (OLED). However, indium has become increasingly expensive and rare because of its limited resources. In addition, ITO thin films have some problems for OLED and flexible displays, such as imperfect work function, chemical instability, and high deposition temperature. Therefore, multi-component TCO materials have been reported as anode materials. Among the various materials, IZTO thin films have been gained much attention as anode materials due to their high work function, good conductivity, high transparency and low deposition temperature. IZTO thin films with a thickness of 200nm were deposited on Corning glass substrate at different substrate temperature by pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt%, ZnO 15 wt%, SnO2 15 wt%). We investigated the electrical, optical, structural properties of IZTO thin films. As the substrate temperature is increased, the electrical properties of IZTO are improved. All IZTO thin films have good optical properties, which showed an average of transmittance over 80%. These IZTO thin films were used to fabricate organic light emitting diodes (OLEDs) as anode and the device performances studied. As a result, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.268-268
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• 2010

The performance dependence of the P3HT:PCBM based bulk hetero-junction (BHJ) organic solar cells (OSCs) on the electrical and the optical properties of amorphous InZnSnO (a-IZTO) electrodes as a difference in film thicknesses are examined. With an increasing of the a-IZTO thickness, the series resistance ($R_{series}$) of the OSCs is reduced because of the reduction of sheet resistance ($R_{sheet}$) of a-IZTO electrodes. Additionally, It was found that the photocurrent density ($J_{sc}$) and the fill factor (FF) in OSCs are mainly affected by the electrical conductivity of the a-IZTO anode films rather than the optical transparency at thinner a-IZTO films. On the other hand, despite the much lower $R_{series}$ comes from thicker anode films, the dominant factor affecting the $J_{sc}$ became average optical transmittance of a-IZTO electrodes as well as power conversion efficiency (PCE) in same device configuration due to the thick anode films had as sufficiently low $R_{sheet}$ to extract the hole carrier from the active material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.379-379
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• 2007

The characteristics of indium-zinc-tin-oxide (IZTO)-Ag-IZTO multilayer grown on a PET substrate were investigated for flexible organic light-emitting diodes. The IZTO-Ag-IZTO (IAI) multilayer anode exhibited a remarkably reduced sheet resistance of 4 ohm/sq and a high transmittance of 84%, despite the very thin thickness of the IZTO (30 nm) layer. In addition, it was shown that electrical and optical properties of IAI anodes are critically dependent on the thickness of the Ag layer, due to the transition of Ag atoms from distinct islands to continuous films at a critical thickness (14 nm). Moreover, the IAI/PET sample showed more stable mechanical properties than an amorphous ITO/PET sample during the bending test due to the existence of a ductile Ag layer. The current density voltage-luminance characteristics of flexible OLEDs fabricated on an IAI/PET substrate was better than those of flexible OLEDs fabricated on an ITO/PET substrate. This indicates that IAI multilayer anodes are promising flexible and transparent electrodes for flexible OLEDs.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.168-168
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• 2010

Transparent conduction oxides (TCOs) films is extensively reported for optoelectronic devices application such as touch panels, solar cells, liquid crystal displays (LCDs), and organic light emitting diodes(OLEDs). Among the many TCO film, indium tin oxide(ITO) is in great demand due to the growth of flat panel display industry. However, indium is not only high cost but also its deposits dwindling. Therefore, many studies are being done on the transparent conductive oxides(TCOs). We fabricated a target of IZTO(In2O3:ZnO:SnO2=70:15:15 wt.%) reduced indium. Then, IZTO thin films were deposited on glass substrates by pulsed DC magnetron sputtering with various oxygen flow ratio. The substrate temperature was fixed at the room temperature. We investigated the electrical, optical, structural properties of IZTO thin films. The electrical properties of IZTO thin films were dependent on the oxygen partial pressure. As a result, the most excellent properties of IZTO thin films were obtained at the 3% of oxygen flow rate with the low resistivity of $7.236{\times}10^{-4}{\Omega}cm$. And also the optical properties of IZTO thin films were shown the good transmittance over 80%. These IZTO thin films were used to fabricated organic light emitting diodes(OLEDs) as anode and the device performances studied. The OLED with an IZTO anode deposited at optimized deposition condition showed good brightness properties. Therefore, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.