• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.181-187
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• 1998

The ionization energy and degree of ionization for p-type $Si_{1-x}Ge_x$ with boron doping are calculated taking into account the screening and broadening effects. The drift and Hall mobilities are then calculated using the relaxation time approximation and compared with the previously reported measurement data for relaxed and strained $Si_{1-x}Ge_x$ alloys to estimate the alloy scattering potential. From a fit, the alloy scattering potential is found to be 0.5 eV. The in-plane drift mobility for p-type strained $Si_{1-x}Ge_x$ grown on (001) Si substrate is approximately 1+$10x^2$ times higher than that for bulk Si in the high doping range.

• Journal of the Semiconductor & Display Technology
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• v.11 no.1
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• pp.1-5
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• 2012

Al doped ZnO (AZO) thin film was deposited by using Facing Target Sputtering (FTS) system. This work examined the properties of AZO thin film as a function of the substrate temperature. The sputtering targets were 4 inch diameter disks of AZO (ZnO : $Al_2O_3$ = 98 : 2 wt.% ). The properties of electrical, structural and optical were investigated by 4-point probe, Hall effect measurement, x-ray diffractometer (XRD), field-emitting scanning electron microscopy (FE-SEM), and UV/VIS spectrometer. The lowest resistivity of films was $5.67{\times}10^{-4}{\Omega}.cm$ and the average optical transmittance of the films was above 85% in the visible range.

• Journal of Korea Foundry Society
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• v.17 no.1
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• pp.76-84
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• 1997

An investigation of the effects of transverse magnetic field on melt convection and macrosegregation in vertical Bridgman growth of Te doped InSb was carried out by means of microstructure observation, the measurement of Te distribution by Hall measurement, electrical resistivity measurement and X-ray analysis. Prior to the experiments, interface stability, convective instability and suppression of convection by magnetic field were examined. A thermosolutal convection in the Te doped InSb melt occurred in the examined growth condition without magnetic field. The effective distribution coefficient, $K_{eff}$, was about 0.35 without magnetic field, 0.45 with magnetic field of 2kG, and 0.7 at 4kG. It was found that the stronger the applied magnetic field was, the more the convection was suppressed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.558-564
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• 2012

We fabricated Ga doped ZnO (GZO) thin films on the glass substrate (Eagle 2000) with various of Ga doping concentration and annealing temperatures using sol-gel method, electrical and optical properties were investigated. When the GZO thin films doped with 1 mol% of Ga and annealed at $600^{\circ}C$, the excellent (002) orientation was observed. In the results of Hall measurement, carrier concentration decreased and resistivity increased due to segregation effect with increasing of the Ga doping concentration. The largest carrier concentration and lowest resistivity were $9.13{\times}10^{18}cm^{-3}$ and $0.87{\Omega}cm$, respectively, in the GZO thin films doped with 1 mol% Ga and annealed at $600^{\circ}C$. All films is higher than 80 % in the visible light region. Energy band gap narrowing due to Burstein-Moss effect was observed with increasing of Ga doping concentration from 1 to 4 mol%.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.6
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• pp.274-284
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• 2001

A stoichimetric mixture of evaporating materials for $AgInS_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films. $AgInS_2$mixed crystal was deposited on thorughly etched semi-insulating GaAs(100) substrate by the Hot wall Epitaxy (HWE) system. The source and substrate temperatures were $680^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of $AgInS_2$ single crystal the films measured from Hall effect by van der Pauw method are $9.35\times 10^{16}/\terxtm{cm}^3$ and $294\terxtm{cm}^2$/V.s at 293 K, respectively. From the optical absorption measurement the temperature dependence of the energy band gap on AgInS$_2$ single crystal thin film was found to be $E_g$(T)= 2.1365eV-($9.89\times 10^{-3}eV/T^2$/(2930+T). After the as-grown $AgInS_2$ single crystal thin films was annealed in $Ag^-S^-$ and In-atmospheres, the origin of point defects of AgInS$_2$ single crystal the films has been investigated by using the photoluminescence(PL) at 10K. The native defects of $V_{Ag},V_s, Ag_{int}$ and $S_{int}$ int/ obtained from PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the S-atmosphere converted $AgInS_2$ single crystal thin films to an optical p-type. Also, we confirmed that In in $AgInS_2$ /GaAs did not form the native defects because In is $AgInS_2$ single crystal thin films did exist in the form of stable bonds.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.293-299
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• 2009

Many kinds of problems by stack effect occur in the high-rise buildings that have the simple plan on the first floor designed only by an external wall and an E/V shaft wall. Therefore, some buildings in the foreign countries has made the additional inside walls between lobby and E/V hall as a countermeasure on stack effect. An additional wall in the lobby is very useful countermeasure on stack problems because lobby is a main airflow path in the building. Decreasing effect on stack problems by an additional wall of lobby is reported in this study. An ordinary office building that has a simple lobby plan is simulated and measured in this study. The results show that characteristics on stack effect are changed by methods of applying additional walls and that alternations of countermeasures which building conditions like the kinds of problems and the problem's velocity etc. are considered are very important.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.6
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• pp.445-454
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• 2001

The stochiometric mix of evaporating materials for the CuInSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuInSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were 62$0^{\circ}C$ and 41$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CuInSe$_2$ single crystal thin films measured from Hall effect fby van der Pauw method are 9.62x10$^{16}$ cm$^{-3}$ , 296$\textrm{cm}^2$/V.s at 293 K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film we have found that he values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 6.1 meV and 175.2 meV at 10K, respectively. From the photoluminescence measurement on CuInSe$_2$ single crystal thin film we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excition were 7meV and 5.9meV, respectivity. by Haynes rule, an activation energy of impurity was 50 meV.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1559-1563
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• 2011

We fabricated gallium doped ZnO (GZO, 5 wt% Ga) thin films on PES (polyethersulfon) substrate with RF magnetron sputtering and investigated optical and electrical properties for various substrate temperatures ($50{\sim}200^{\circ}C$). All GZO thin film has c-axis preferred orientation without reference to deposition conditions. As a result of AFM analysis, the GZO thin film deposited at $200^{\circ}C$ exhibited the lowest surface roughness of 0.196nm. The transmittance of GZO thin films were above 80% and Burstein-Moss effect was observed. In the analysis of Hall measurement, we confirmed that the GZO thin film deposited at $200^{\circ}C$ showed the lowest resistivity of $6.93{\times}10-4{\Omega}{\cdot}cm$ and the highest carrier concentration of $7.04{\times}1020/cm^3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.257-265
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• 2002

A stoichiometric mixture of evaporating materials for AgInS$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, AgInS$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy(HWE) system. The source and substrate temperatures were 680 $^{\circ}C$ and 410 $^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of AgInS$_2$ single crystal thin films measured from Hall effect by van der Pauw method are 9.35${\times}$10$\^$16/ cm$\^$-3/ and 294 $\textrm{cm}^2$/V$.$s at 293 K, respectively. From the optical absorption measurement, the temperature dependence of the energy band gap on AgInS$_2$ single crystal thin films was found to be E$\_$g/(T) : 2.1365 eV - (9.89 ${\times}$ 10$\^$-3/ eV) T$^2$/(2930 + T). After the as-grown AgInS$_2$ single crystal thin films was annealed in Ag-, S-, and In-atmospheres, the origin of point defects of AgInS$_2$ single crystal thin films has been investigated by using the photoluminescence(PL) at 10 K. The native defects of V$\_$AG/, V$\_$S/, Ag$\_$int/, and S$\_$int/ obtained from PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the S-atmosphere converted AgInS$_2$ single crystal thin films to an optical p-type. Also, we confirmed that In in AgInS$_2$/GaAs did not form the native defects because In in AgInS$_2$ single crystal thin films did exist in the form of stable bonds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.163-166
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• 2001

The stochiometric mix of evaporating materials for the $ZnGa_{2}Se_{4}$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $ZnGa_{2}Se_{4}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $ZnGa_{2}Se_{4}$ single crystal trun films measured from Hall effect by van der Pauw method are $9.63{\times}10^{17}cm^{-3}$, $296cm^{2}/V{\cdot}s$ at 293 K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c axis of the $ZnGa_{2}Se_{4}$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$ So and the crystal field splitting $\Delta$Cr were 251.9 meV and 183.2 meV at 10 K, respectively. From the photoluminescence measurement on $ZnGa_{2}Se_{4}$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton $(A^{0},X)$ having very strong peak intensity. Then, the full-width-at -half-maximum(FWHM) and binding energy of neutral acceptor bound excition were 11 meV and 24.4 meV, respectivity. By Haynes rule, an activation energy of impurity was 122 meV.