• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.219-222
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• 2007

Highly conductive and transparent aluminum doped ZnO thin films (AZO) films have been prepared by r.f. magnetron sputtering processes on poly carbonate (PC) and onto glass as reference. In addition, the electrical, optical properties of the films prepared at various sputtering powers were investigated. The XRD measurements revealed that all of the obtained films were polycrystalline with the hexagonal structure and had a preferred orientation with the c-axis perpendicular to the substrate. The ZnO:Al films were increasingly dark gray colored as the sputter power increased, resulting in the loss of transmittance. High quality films with the resistivity as low as $9.7{\times}10^{-4}\;{\Omega}-cm$ and transmittance over 90% have been obtained by suitably controlling the r.f. power.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.121.2-121.2
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• 2011

Aluminum-doped Zinc Oxide (AZO) is considered as an excellent candidate to replace Indium Tin Oxide (ITO), which is widely used as transparent conductive oxide (TCO) for electronic devices such as liquid crystal displays (LCDs), organic light emitting diodes (OLEDs) and organic solar cells (OSCs). In the present study, AZO thin film was applied to the transparent electrode of a channel-shaped flexible organic solar cell using a low-temperature selective-area atomic layer deposition (ALD) process. AZO thin films were deposited on Poly-Ethylene-Naphthalate (PEN) substrates with Di-Ethyl-Zinc (DEZ) and Tri-Methyl-Aluminum (TMA) as precursors and $H_2O$ as an oxidant for the atomic layer deposition at the deposition temperature of $130^{\circ}C$. The pulse time of TMA, DEZ and $H_2O$, and purge time were 0.1 second and 20 second, respectively. The electrical and optical properties of the AZO films were characterized as a function of film thickness. The 300 nm-thick AZO film grown on a PEN substrate exhibited sheet resistance of $87{\Omega}$/square and optical transmittance of 84.3% at a wavelength between 400 and 800 nm.

• Journal of the Korean institute of surface engineering
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• v.40 no.3
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• pp.107-112
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• 2007

Aluminum doped zinc oxide (AZO) films were deposited on non-alkali glass substrate by DC magnetron sputtering with 3 types of AZO targets (doped with 1.0 wt%, 2.0 wt%, 3.0 wt% $Al_2O_3$). Electrical, optical properties and microstructure of AZO films have been investigated by Hall effect measurements, UV/VIS/NIR spectrophotometer, and XRD, respectively. Crystallinity of AZO films increased with increasing substrate temperature ($T_s$) and doping ratio of Al. Resistivity and optical transmittance in visible light were $8.8{\times}10^{-4}{\Omega}cm$ and above 85%, respectively, for the AZO film deposited using AZO target (doped with 3.0 wt% $Al_2O_3$) at $T_s$ of $300^{\circ}C$. On the other hand, transmittance of AZO films in near-infrared region decreased with increasing $T_s$ and doping ratio of Al, which could be attributed to the increase of carrier density.

• Journal of the Korean institute of surface engineering
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• v.42 no.3
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• pp.128-132
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• 2009

Transparent conducting thin films of indium tin oxide(ITO) co-sputtered with aluminum-doped zinc oxide(AZO) were deposited on glass substrate by dual magnetron sputtering. It was found that the electrical properties and structural characteristics of the films are significantly changed according to the sputtering power of the AZO target. The IAZTO film prepared with D.C power of ITO at 100 W and R.F power of AZO at 50 W shows an electrical resistivity of $4.6{\times}10^{-4}{\Omega}{\cdot}cm$ and a sheet resistance of $30{\Omega}/{\square}$ (for 150 nm thick). Besides of the improvement of the electrical properties, compared to the ITO films deposited at the same process conditions, the IAZTO films have very smooth surface, which is due to the amorphous nature of the films. However, the electrical conductivity of the IAZTO films was found to be deteriorated along with the crystallization in case of the high temperature deposition (above $310^{\circ}C$). In this work, high quality amorphous transparent conductive oxide layers could be obtained by mixing AZO with ITO, indicating possible use of IAZTO films as the transparent electrodes in OLED and flexible display devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.331-331
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• 2008

Transparent conductive oxide (TCO) are necessary as front electrode or anti-reflecting coating for increasing efficiency of LED and Photodiode. In this paper, aluminum-doped Zinc oxide films(AZO) were prepared by RF magnetron sputtering on Si substrate at room temperature with application of substrate bias from -60 to 60 V. Then annealed at temperature of 200, 300 and $400^{\circ}C$ for 1hr in $H_2$ ambient. Structural and electrical property of AZO thin films were investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.444-445
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• 2007

Aluminum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). AZO films have been deposited on glass (coming 1737) substrates by RF magnetron sputtering system. An ultrathin layer of nickel oxide (NiO) was deposited on the AZO anode to enhance the hole injections in organic light-emitting diodes (OLED). The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.91-92
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• 2006

Aluminum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering system. The electrical resistivity of AZO films was $1.81{\times}10^{-2}{\Omega}cm$ and the average transmittance in the visible range 400-800 nm was more than 76% Organic light-emitting diodes (OLEDs) with AZO/TPD/$Alq_3$/Al configuration were fabricated. The current density-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.9
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• pp.378-382
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• 2003

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCI (0.5%) to examine the electrical and surface morphology properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure md the substrate temperature. In low pressures (0.9mTorr) and high substrate temperatures ($\leq$$300^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.391-394
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• 2002

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology Properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9 mTorr) and high substrate temperatures ($\leq$30$0^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.500-501
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• 2005

Aluminum doped zinc oxide films (ZnO:Al) were deposited on glass substrate by DC magnetron sputtering from a ZnO target mixed with 2 wt% $Al_2O_3$. The effects of substrate bias on the electrical properties and film structure were studied. Films deposited with positive bias have been annealed at $600^{\circ}C$ using rapid thermal anneal (RTA) process. The effects of RTA on the evolution of film microstructure are to be also studied using X-ray diffraction, transmission electron microscopy, and atomic force microscopy. Positive bias sputtering may induce lattice defects caused by electron bombardments during deposition. The as-deposited film microstructure evolves from the film with high defect density to more stable film condition. The electrical properties of the films after RTA process were also studied and the results were correlated with the evolution of film microstructures.