• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.1-5
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• 2021

Field-effect transistors based on solution-processed metal oxide semiconductors has attracted huge attention due to their intrinsic characteristics of optical and electrical characteristics with benefits of simple and low-cost process. Especially, spray-pyrolysis has shown excellent device performance which compatible to vacuum-processed Field-effect transistors. However, the high annealing temperature for crystallization of MOS and narrow range of precursors has impeded the progress of the technology. Here, we demonstrated the nc-ZnO/ZnO films performed by spray-pyrolysis with incorporating ZnO nanoparticles into typical ZnO precursor. The films exhibit preserving morphological properties of poly-crystalline ZnO and enhanced electrical characteristics with potential for low-temperature processability. The influence of nanoparticles within the film was also researched for realizing ZnO films providing good quality of performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.256-256
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• 2008

We report epitaxial growth of ZnO thin films on (100) single-crystalline $LaAlO_3$ (LAO) substrates using pulsed laser deposition (PLD) at different substrate temperatures (400~$800^{\circ}C$). The structural and electrical properties of the films have been investigated by means of X-ray diffraction (XRD), atomic force microscope (AFM), transmission line method (TLM). The poly-crystalline of $\alpha$- and c-axis oriented ZnO film was formed at lower deposition temperature ($T_s$) of $400^{\circ}C$. At higher $T_s$, however, the films exhibit single-crystalline of $\alpha$-axis orientation represented by ZnO[$\bar{1}11$ || LAO <001>. The electrical properties of ZnO thin films depend upon their crystalline orientation, showing lower electrical resistivity values for $\alpha$-axis oriented ZnO films.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.3
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• pp.194-197
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• 2013

We investigated the effect of etching time on the surface roughness, and electrical and optical properties of ZnO and 2 wt% Al-doped ZnO (AZO) films. The ZnO and AZO films were deposited on glass substrates by RF magnetron sputtering technique. The etching experiment was carried out using a solution of 5% HCl at room temperature. The surface roughness was characterized by Atomic Force Microscopy. The electrical property was measured by Hall measurement system and 4-point probe. The optical property was characterized by UV-vis spectroscopy. After the wet chemical etching, the surface textures were obtained on the surface of the ZnO and AZO films. With the increase of etching time, the surface roughness (RMS) of the films increased and the transmittance of the films was observed to decrease. For the AZO film, a low resistivity of $1.0{\times}10^{-3}\;{\Omega}{\cdot}cm$ was achieved even after the etching.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.108-111
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• 2001

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition(PLD) technique for light emitting device applications. We have controlled the emission intensity of UV and visible light, depending on film thickness and various post-annealing time. UV emission became strong as the thickness of ZnO thin films increased. The intensity of visible light was strong as post-annealing temperature increased. The optical properties of the ZnO thin films were characterized by PL(photoluminescence) and the structural properties of the ZnO were characterized by XRD for the application of ZnO light emission device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.108-111
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• 2001

ZnO thin films on (001) sapphire substrates knave been deposited by pulsed laser deposition(PLD) technique for light emitting device applications. We have controlled the emission intensity of UV and visible light, depending on film thickness and various post-annealing time. UV emission became strong as the thickness of ZnO thin films increased. The intensity of visible light was strong as post-annealing temperature increased. The optical properties of the ZnO thin films were characterized by PL(photoluminescence) and the structural properties of the ZnO were characterized by XRD for the application of ZnO light emission device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.200-202
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• 2004

ZnO thin films were grown at different plume-substrate angles by pulsed laser deposition(PLD). From the X-ray diffraction(XRD) result, all ZnO thin films were found to be well c-axis oriented and c-axis lattice constant approached the value of bulk ZnO as plume-substrate(P-S) angle decreased. The grain size of ZnO thin films measured by atomic force microscopy increased and the UV intensity of ZnO thin films investigated by photoluminescence increased as P-S angle decreased. It is found that the improvement of structural and optical properties mainly comes from the reduction of the flux of ablated species arriving on a substrate per a laser shot by tilting a substrate parallel to the plume propagation direction.

• Journal of the Korean Vacuum Society
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• v.22 no.1
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• pp.20-25
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• 2013

ZnO:Al thin films deposited by RF magnetron sputtering were post-annealed and the electrical and optical properties of ZnO:Al thin films were investigated before and after anneling. We confirmed that the ZnO:Al thin film was affected by post-annealing temperature. As post-annealing temperature increases, crystallinity and transmittance in visible area (400~800 nm) of ZnO:Al thin films decreased. While sheet resistance of thin films increased sharply with increasing to $400^{\circ}C$. This result is due to reduce of carrier concentration caused by absorption of $O_2$ or $N_2$ at surface of thin film.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1627-1630
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• 2004

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition(PLD) technique using an Nd:YAG laser with a wavelength of 266nm. Before post-annealing treatment in the oxygen ambient, the experiment of the deposition of ZnO thin films has been performed for substrate temperatures in the range of $300{\sim}450^{\circ}C$ and flow rate of 100${\sim}$700 seem. In order to investigate the effect of post-annealing treatment of ZnO thin films, films have been annealed at various temperatures after deposition. After post-annealing treatment in the oxygen ambient, the structural properties of ZnO thin films were characterized by X-ray diffraction(XRD) and the optical properties of the ZnO were characterized by photoluminescence(PL).

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.302.1-302.1
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• 2014

We report the growth of high quality zinc oxide (ZnO) thin films on amorphous glass substrates and their structural and optical characteristics. For the growth of ZnO films, mechanically exfoliated ultrathin graphite or graphene layers were used as an intermediate layer because ZnO does not have any heteroepitaxial relationship with the amorphous substrates, which significantly improved the crystallinity of the ZnO films. Structural and optical characteristics of the films were investigated using scanning and transmission electron microscopy, x-ray diffraction, and variable temperature photoluminescence spectroscopy. High crystallinity and excellent optical characteristics such as stimulated emission were exhibited from the high quality ZnO films grown on glass substrates.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.738-742
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• 2006

We report on the effects of co-doping with fluorine on properties of ZnO thin films grown by pulsed-laser deposition. The transport characteristics of Ag-F and Li-F codoped ZnO films were determined by Hall-effect measurements at room temperature. Ag-F codoped ZnO films showed n-type semiconducting behaviors. An ambiguous carrier type was observed in Li-F codoped ZnO films grown at a temperature of 500$^{\circ}C$ with the oxygen pressures of 20 and 200 mTorr. The qualities of the codoped ZnO films were studied by X-ray diffraction, atomic force microscopy, X-ray photoemission spectroscopy, and photoluminescence.