• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.262-264
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• 2014

Pristine ZnO, 3 wt.% Ga-doped (3GZO) and 3 wt.% Ag-doped (3SZO) ZnO nanowires (NWs) were grown using the hot-walled pulse laser deposition (HW-PLD) technique. The doping of Ga and Ag in ZnO NWs was observed by analyzing the optical and chemical properties. We optimized the synthesis conditions, including processing temperature, time, gas flow, and distance between target and substrate for the growth of pristine and doped ZnO NWs. The diameter and length of pristine and doped ZnO NWs were controlled under 200 nm and several ${\mu}m$, respectively. Low temperature photoluminescence (PL) was performed to observe the optical property of doped NWs. We clearly observed the shift of the near band edge (NBE) emission by using low temperature PL. In the case of 3GZO and 3SZO NWs, the center photon energy of the NBE emissions shifted to low energy direction using the Burstein Moss effect. A strong donor-bound exciton peak was found in 3 GZO NWs, while an acceptor-bound exciton peak was found in 3SZO NWs. X-ray photoelectron spectroscopy (XPS) also indicated that the shift of binding energy was mainly attributed to the interaction between the metal ion and ZnO NWs.

• Journal of the Korean Ceramic Society
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• v.51 no.1
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• pp.43-50
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• 2014

We fabricated undoped and Sb-doped $SnO_2$ thin films on glass substrates by a pulsed laser deposition (PLD) process. Undoped and 2 - 8 wt% $Sb_2O_3$-doped $SnO_2$ targets with a high density level of ~90% were prepared by the spark plasma sintering (SPS) process. Initially, the effects of the deposition temperature on undoped $SnO_2$ thin films were investigated in the region of $100-600^{\circ}C$. While the undoped $SnO_2$ film exhibited the lowest resistivity of $1.20{\times}10^{-2}{\Omega}{\cdot}cm$ at $200^{\circ}C$ due to the highest carrier concentration generated by the oxygen vacancies, 2 wt% Sb-doped $SnO_2$ film exhibited the lowest resistivity value of $5.43{\times}10^{-3}{\Omega}{\cdot}cm$, the highest average transmittance of 85.8%, and the highest figure of merit of 1202 ${\Omega}^{-1}{\cdot}cm^{-1}$ at $400^{\circ}C$ among all of the doped films. These results imply that 2 wt% $Sb_2O_3$ is an optimum doping content close to the solubility limit of $Sb^{5+}$ substitution for the $Sb^{4+}$ sites of $SnO_2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.27-27
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• 2008

The different concentration Indium doped ZnO:Al films were grown on glass substrates (Corning 1737) at $200^{\circ}C$ by pulsed laser deposition. The indium doping in AZO films shows the critical effect on the crystallinity, resistivity, and optical properties of the films. The AZO films doped with 0.3 atom % indium content exhibit the highest crystallinity, the lowest resistivity of $4.5\times10^{-4}\Omega$-cm, and the maximum transmittance of 93%. The resistivity of the indium doped-AZO films is strongly related with the crystallinity of the films. The carrier concentration in the indium doped-AZO films linearly increases with increasing indium concentration. The mobility of the AZO films with increasing indium concentration was reduced with an increase in carrier concentration and the decrease in mobility was attributed to the ionized impurity scattering mechanism. In an optical transmittance, the shift of the optical absorption edge to shorter wavelength strongly depends on the electronic carrier concentration in the films.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.476-480
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• 2004

AZO (Al-doped ZnO) thin films were deposited on glass by pulsed magnetron sputtering method, and their structural, electrical and optical properties were investigated. XRD patterns showed that a highly c-axis preferred AZO film was grown in perpendicular to the substrate when pulse frequency of 30 ㎑ was applied to the target. Microstructure of thin films showed that the fibrous grain of tight dome shape was grown. The deposition rate decreased linearly with increase of pulse frequency, and the lowest resistivity was 8.67${\times}$10$\^$-4/ $\Omega$-cm for the film prepared at pulse frequency of 30 ㎑. The optical transmittance spectra of the films showed a very high transmittance of 85∼90%, within visible wavelength region and exhibited the absorption edge of about 350 nm. The characteristics of the low electrical resistivity and high optical transmittance of AXO films suggested a possibility for the application to transparent conducting oxides.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.10-11
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• 2003

Metal nanoparticle doped glasses have various applications such as use as photochromic media for optical disk data storage, the fabrication of optical waveguides and waveguide lasers, use as all-optical switches due to their nonlinear optical properties, as well as use in the color glass recycling industry. Recently, an ultrashort pulsed laser has been used as a powerful tool to make microscopic modifications to transparent Metal nano particle doped glasses. (omitted)

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1782-1785
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• 2007

In this paper, the effect of substrate temperature on structural, electrical and optical properties of aluminium-doped zinc oxide (AZO) films were investigated. AZO thin films were prepared on glass substrate by pulsed DC magnetron sputtering technique. The properties of AZO were measured by using XRD, AFM, UV spectrophotometer, and hall effect measurement system. The resistivity of AZO films was improved under the condition of high substrate temperature. The resistivity decreased from $9.95{\times}10^{-2}\;{\Omega}-cm\;to\;1.1{\times}10^{-3}\;{\Omega}-cm$ as a result of high substrate temperature and the average transmittances in visible range were above 80%.

• Transactions on Electrical and Electronic Materials
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• v.3 no.1
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• pp.1-3
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• 2002

A p-n junction was obtained by the deposition of an n-type ZnO thin film on a p-type Zn-doped InP substrate. The Zn-doped InP substrate has been made by the diffusion of Zn with sealed ampoule technique. The ZnO deposition process was performed by pulsed laser deposition (PLD). The p-n junction was formed and showed typical I-V characteristics. We will also discuss about the realization of an ultraviolet light-emitting diode (LED). The structure of n-ZnO/p-Zn-doped InP could be a good candidate for the realization of an ultraviolet light-emitting diode or an ultraviolet laser diode.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.148-151
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• 2013

The control of Ga doping in ZnO nanowires (NWs) by physical vapor deposition has been implemented and characterized. Various Ga-doped ZnO NWs were grown using the vapor-liquid-solid (VLS) method, with Au catalyst on c-plane sapphire substrate by hot-walled pulsed laser deposition (HW-PLD), one of the physical vapor deposition methods. The structural, optical and electrical properties of Ga-doped ZnO NWs have been systematically analyzed, by changing Ga concentration in ZnO NWs. We observed stacking faults and different crystalline directions caused by increasing Ga concentration in ZnO NWs, using SEM and HR-TEM. A $D^0X$ peak in the PL spectra of Ga doped ZnO NWs that is sharper than that of pure ZnO NWs has been clearly observed, which indicated the substitution of Ga for Zn. The electrical properties of controlled Ga-doped ZnO NWs have been measured, and show that the conductance of ZnO NWs increased up to 3 wt% Ga doping. However, the conductance of 5 wt% Ga doped ZnO NWs decreased, because the mean free path was decreased, according to the increase of carrier concentration. This control of the structural, optical and electrical properties of ZnO NWs by doping, could provide the possibility of the fabrication of various nanowire based electronic devices, such as nano-FETs, nano-inverters, nano-logic circuits and customized nano-sensors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.355-356
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• 2008

In this work, ZnO films doped with different contents of Indium (0.1at.%, 0.3at.%, 0.6at.%, respectively) were deposited on Si (111) substrate that has 1~20 $\Omega$cm by pulsed laser deposition (PLD) at $600^{\circ}C$ for 30min. The thickness of the films are about 250 nm. The structural, optical and electrical properties of the films were investigated using X-ray Diffraction (XRD), Atomic force microscope (AFM), Photoluminescence (PL) and Hall measurement. It has been found that RMS of the films is decreased and grain size is increased with increasing the contents of doped Indium. The results of the Photoluminescence properties were indicated that the films have UV emission about 380nm and shows a little red shitf with increasing contents of doped indium. The result of the Hall measurement shows that the concentration and resisitivity in doped ZnO are as changing as one order, respectively ${\sim}10^{18}/cm^2$, ${\sim}10^{-2}cm{\Omega}cm$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.10
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• pp.814-820
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• 2009

Antimony (Sb) doped ZnO thin films (0.1 at.%) were deposited on sapphire (0001) substrates at various temperatures (200 - 600$^{\circ}C$) by using pulsed laser deposition technique. All the thin films have been characterized by X-ray diffractometer, atomic force microscopy and spectrophotometer to investigate their structural, morphological and optical properties, respectively. Hall measurements were also carried out to identify the electrical properties of the thin films. These thin films were constituted in wurtzite structure with the preferential orientation of (002) diffraction plane and had as high as 80% optical transmission in the visible range. The bandgap energy also was determined by spectrophotometer which was around 3.28 eV. Hall measurements results revealed that the Sb dope ZnO thin film (0.1 at.%) grown at $500^{\circ}C$ exhibited p-type conduction with a carrier concentration of $8.633\times10^{16}\;cm^{-3}$, a mobility of $1.41\;cm^2/V{\cdot}s$ and a resistivity of $51.8\;\Omega{\cdot}cm$. We have successfully achieved p-type conduction in antimony doped ZnO thin films with low doping level even though the electrical properties are not favorable. This paper suggests the feasibility of p-type doping with large-size-mismatched dopant by using pulsed laser deposition.