• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.344-348
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• 2004

The CdSe thin films wee grown on the Si(100) wafers by a hot wall epitaxy method(HWE). The source and substrate temperature are $600^{\circ}C\;and\;430^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the timperature range 30K to 150K by impurity scatering and decreased in the temperature range 150K to 293K by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.39{\times}10^7$, the MAPD of 335mV, and the rise and decay time of 10ms and 9.5ms, respectively

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.263-266
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• 2004

The stochiometric mix of evaporating materials for the $ZnGa_2Se_4$ single crystal thin films were prepared from horizental furnace. The polycrystal structure obtaind from the power x-ray diffraction was defect chalcopyrite. The lattice costants $a_0\;and\;c_0\;were\;a_0=5.51\;A,\;c_0=10.98\;A$. To obtains the single crystal thin films, $ZnGa_2Se_4$ mixed crystal were deposited on throughly etched Si(100) by the Hot Wall Epitaxy (HWE) system. The temperates of the source and the substrate were $590^{\circ}C\;and\;450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to dark current(pc/dc), maximum allowable rower dissipation(MAPD), spectral response and response time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.304-308
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• 2004

The $Cd_{1-x}Zn_xS$ thin films were grown on the Si(100) wafers by a hot wall epitaxy method(HWE). The source and substrate temperature are $600^{\circ}C\;and\;440^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the $Cd_{0.53}Zn_{0.47}S$ samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.65{\times}10^7$, the MAPD of 338mW, and the rise and decay time of 9.7ms and 9.3ms, respectively

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.381-384
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• 2004

The stochiometric nix of evaporating materials for the $AgInS_2$ single crystal thin films were prepared from horizontal furnace. The polycrystal structure obtaind from the power x-ray diffraction was chalcopyrite. The lattice costants $a_0\;and\;c_0$ were $a_0=5.86(5.82)\;A,\;c_0=11.355(11.17)\;A$. To obtains the single crystal thin films, $AgInS_2$ mixed crystal were deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy(HWE) system. The temperates of the source and the substrate were $590^{\circ}C\;and\;450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time.

• Transactions on Electrical and Electronic Materials
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• 제11권1호
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• pp.15-19
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• 2010

In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a $0.35\;{\mu}m$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and $1.5\;{\mu}m$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($i_{SUB}$), drain to source leakage current ($i_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.125-126
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• 2006

The stochiometric mix of evaporating materials for the $CdGa_2Se_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films. $CdGa_2Se_4$ 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 $630^{\circ}C$ and $420^{\circ}C$, 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 $CdGa_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $8.27{\times}10^{17}cm^{-3}$. $345cm^2/V{\cdot}s$ at 293 K, respectively. From the photoluminescence measurement on $CdGa_2Se_4$ single crystal thin film, we observed free excition ($E_x$) 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 8 meV and 13.7 meV, respectivity. By Haynes rule. an activation energy of impurity was 137 meV.

• Journal of Sensor Science and Technology
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• 제16권6호
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• pp.419-427
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• 2007

Single crystal $ZnIn_{2}S_{4}$ layers were grown on a thoroughly etched semi-insulating GaAs(100) substrate at $450^{\circ}C$ with the hot wall epitaxy (HWE) system by evaporating the polycrystal source of $ZnIn_{2}S_{4}$ at $610^{\circ}C$ prepared from horizontal electric furnace. 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 single crystal $ZnIn_{2}S_{4}$ thin films measured with Hall effect by van der Pauw method are $8.51{\times}10^{17}\;electron/cm^{-3}$, $291{\;}cm^{2}/v-s$ at 293 K, respectively. The photocurrent and the absorption spectra of $ZnIn_{2}S_{4}$/SI(Semi-Insulated) GaAs(100) are measured ranging from 293 K to 10 K. The temperature dependence of the energy band gap of the $ZnIn_{2}S_{4}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)$=2.9514 eV. ($7.24{\times}10^{-4}\;eV/K$)$T^{2}$/(T+489 K). Using the photocurrent spectra and the Hopfield quasicubic model, the crystal field energy(${\Delta}cr$) and the spin-orbit splitting energy(${\Delta}so$) for the valence band of the $ZnIn_{2}S_{4}$ have been estimated to be 167.8 meV and 14.8 meV at 10 K, respectively. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}$-, $B_{1}$-, and $C_{41}$-exciton peaks.

• Korean Journal of Materials Research
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• 제23권2호
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• pp.98-103
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• 2013

$Mg_{3-x}Zn_xSb_2$ powders with x = 0-1.2 were fabricated by mechanical alloying in a planetary ball mill with a speed of 350 rpm for 24 hrs and then hot pressed under a pressure of 70 MPa at 773 K for 2 hrs. It was found that there were systematic shifts in the X-ray diffraction peaks of $Mg_3Sb_2$ (x = 0) toward a higher angle with increasing Zn for both the powder and the bulk sample and finally the phase of $Mg_{1.86}Zn_{1.14}Sb_2$ was formed at the Zn content of x = 1.2. The $Mg_{3-x}Zn_xSb_2$ compounds had nano-sized grains of 21-30 nm for the powder and 28-66 nm for the hot pressed specimens. The electrical conductivity of hot pressed $Mg_{3-x}Zn_xSb_2$ increased with increasing Zn content and temperature from 33 $Sm^{-1}$ for x = 0 to 13,026 $Sm^{-1}$ for x = 1.2 at 323 K. The samples for all the compositions from x = 0 to x = 1.2 had positive Seebeck coefficients, which decreased with increasing Zn content and temperature, which resulted from the increased charge carrier concentration. Most of the samples had relatively low thermal conductivities comparable to the high performance thermoelectric materials. The dimensionless figure of merit of $Mg_{3-x}Zn_xSb_2$ was directly proportional to the Zn content except for the compound with Zn = 1.2 at high temperature. The $Mg_{3-x}Zn_xSb_2$ compound with Zn = 0.8 had the largest value of ZT, 0.33 at 723 K.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.167-170
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• 2001

The stochiometric mix of evaporating materials for the CdGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdGa$_2$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 630$^{\circ}C$ and 420$^{\circ}C$, 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 CdGa$_2$Se$_4$ single crystal thin films measured from Hall erect by van der Pauw method are 8.27x10$\^$17/ cm$\^$-3/, 345 $\textrm{cm}^2$/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 the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 106.5 meV and 418.9 meV at 10 K, respectively. From the photoluminescence measurement on CdGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$\_$X/) existing only high quality crystal and neutral bound exiciton (D$\^$0/,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excision were 8 meV and 13.7 meV, respectivity. By Haynes rule, an activation energy of impurity was 137 meV,

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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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 61$0^{\circ}C$ and 45$0^{\circ}C$, 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 ZnGa$_2$Se$_4$ single crystal thin films measured from Hall effect by van der Pauw method are 9.63x10$^{17}$ 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 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 (E$_{x}$) existing only high quality crystal and neutral bound excition (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.on energy of impurity was 122 meV.