• Journal of the Korean Vacuum Society
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• v.7 no.2
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• pp.104-111
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• 1998

The InGaAs/InP quantum wells(QWs) were grown by low pressure metalorganic chemical vapor deposition and the effects of growth interruption steps on their interfacial structures were investigated by measuring photoluminescence spectra. When InP or InGaAs surface was treated under the same group V ambient, the full width at half maximum (FWHM) of the QW peak increased possibly due to the incorporation of impurities during the growth interruption time. When InP surface was treated under $AsH_3$, howerer, the PL peak showed red-shift due to the As-P exchange reaction and the change of FWHM was not remarkable. The effective thickness of InAs interfacial layer formed during $AsH_3$, treatment on the InP surface was calculated to be 1~2 monolayers. In the case of InGaAs treatment under $PH_3$, the PL peak energy and the FWHM increasied. This results suggest that $PH_3$ treatment on the InGaAs surface suppresses the incorporation of As into the subsequent InP layer and the local replacement of As by P occurs simultaneously.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1264-1265
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• 2008

PLD 방법으로 undoped ZnO박막을 성장 온도별로 성장하여 박막의 광학적 특성이 변화되는 것을 관찰하였다. undoped ZnO박막은 $Al_2O_3(0001)$기판을 이용하였고, pulsed laser deposition(PLD)을 이용하여 증착을 하였다. 이때 파장이 355nm인 Nd:YAG 레이저를 이용하였고 레이저의 에너지 밀도는 1.4 $J/cm^2$ 이었다. 구조적 광학적 특성을 관측하기 위하여 XRD, SEM, PL 등을 측정하였다. PL 측정 결과 성장 온도가 증가함에 따라 undoped ZnO박막의 광학적 특성이 좋아지는 것을 관찰할 수 있었다. XRD 측정 결과도 온도별 FWHM과 intensity ratio가 점차 좋아지는 것을 볼 수 있었다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.409-410
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• 1989

Discharge characteristics of a commercial made Xe-flashlamp have been studied for the pumping source of dye Lasers. The rise-time, FWHM, intensity and energy of pumping light pulses of the lamp were measured as functions of the serial resistor and applied voltage. The grid effects of the lamp on pre-discharge and the spectrum of light pulses also have been investigated.

• Journal of the Korean Institute of Telematics and Electronics
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• v.4 no.2
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• pp.16-21
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• 1967

This report describes actual fabrication mehod of Li drifted Ge detector. The gamma-ray spectrum from Cl(n, r) reaction measured by this Li drifted Ge detector are also shown. Energy resolution(FWHM) of this Li drifted Ge detector is 4.5KeV at the 122KeV( ), and 10KeV a the 1333KeV( ) respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.712-718
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• 2003

The effects of nitrogen ion implantation on vacuum evaporated cadmium sulphide (CdS) thin films were investigated by X-ray diffraction, optical transmittance spectra, and Raman scattering studies. The as-deposited CdS films have a hexagonal structure with preferential (0 0 2) orientation. Formation of Cd metallic clusters was observed in ion implanted films from the XRD patterns. The band gap of N+ implanted films decreased, whereas the optical absorption coefficient values increased with the increase of implantation dose. The Raman peak position appeared at 299 cm-1 and the FWHM increased with the ion dose. A decrease in the area of Raman peak of CdS Al(LO) mode is seen on implantation.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.84-89
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• 1994

A tunable pulsed dye laser was operated in a single longitudinal mode by injection locking with a cw ring dye laser. A doubled Nd:YAG laser was used as the pumping source. Phase sensitive detection technique was applied to maintain the required match between the master laser frequency and the slave resonator cavity length. The fluctuation of the center frequency of the pulsed laser was < 10 MHz, and the pulse duration (FWHM) was 6 ns. The linewidth measured by scanning confocal interferometer was 130 MHz. When pumped by 50 mJ of the doubled Nd:YAG laser, the output energy of the pulsed dye laser was 2 mJ and the peak power was 330 kW. 30 kW.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.221-225
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• 2007

The possibility of improving amplification characteristics and lowering the melting point of bismuth-doped aluminosilicate glass as a new amplification material, which has broadband near-infrared emission at 1300 nm regions, was investigated. Spectroscopic analysis of bismuth-doped aluminosilicate glass shows that the addition of an alkali metal oxide, $Li_{2}O$ increases FWHM of fluorescence spectrum but decreases fluorescence intensity, while $GeO_{2}$ composition increases both FWHM of fluorescence spectrum and fluorescence intensity. Also, excellent optical amplification gain characteristics in a $GeO_{2}$-added sample were observed.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.450-455
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• 1999

We present Photoluminescence (PL) and Atomic Force Microscopy (AFM) image on InAs quantum dots (QDs) having different size which grown by Molecualr Beam Epitaxy (MBE). For different size QDs, analysis of the AFM profiles show that the density of QDs was the maximum value $(1.1\times10^{11}\textrm{/cm}^2)$ at 2.0 ML. In the spectra of QDs, it is found that the peak energy decreases with increasing dot size due to the effect of quantum confinement. Temperature dependence of PL intensities show that the PL is quenching and Red shift as the temperature increase. The FWHM range of 20K~180K is narrowing with increasing temperature. When temperature is over 180K, the line-width starts to in creases with increasing temperature. At last, temperature dependence of the integrated intensities were fit using the Arrehenius-type function for the activation energy. Fit value of the activation energy was increased with increasing QDs-size.

• Progress in Superconductivity
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• v.3 no.1
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• pp.125-129
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• 2001

NiO buffer layers were deposited on texture Ni tapes fur YBCO coated conductors by MOCVD(metal organic chemical vapor deposition) method, using a single solution source. Variables were deposition temperature and flow rate of $0_2$carrier gas. At higher temperatures, The NiO(111) texture was well developed, but the NiO(200) texture was developed at low temperatures. The best result was obtained at the deposition temperature of$ 470^{\circ}C$ and the gas flow rate of 200 sccm. FWHM value of $\omega$-scan fur NiO(200) of the film and $\Phi$-scan for NiO(111) of the film was $4.2^{\circ}$ and $7^{\circ}$, respectively.

• Progress in Superconductivity
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• v.9 no.1
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• pp.62-67
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• 2007

The effects of the heat-treatment temperature on the carbon (C) substitution amount, full width at half maximum (FWHM) value, critical temperature ($T_c$), critical current density ($J_c$) have been investigated for 10 wt % malic acid ($C_4H_6O_5$)-doped $MgB_2/Fe$ wires. All the samples were fabricated by the in-situ powder-in-tube (PIT) method and heat-treated within a temperature range of $650^{\circ}C$ to $1000^{\circ}C$. As the heat-treatment temperature increased, it seemed that the lattice distortion was increased by a more active C substitution into the boron sites from the malic acid addition. These increased electron scattering defects seemed to enhance the $J_c-H$ properties in spite of an improvement in the crystallinity, such as a decrease of the FWHM value and an increase of the $T_c$. Compared to the un-doped wire heat-treated at $650^{\circ}C$ for 30 min, the $J_c$ was enhanced by the C doping in a high-field regime. The wire heat-treated at $900^{\circ}C$ resulted in a higher magnetic $J_c$ of approximately $10^4\;A/cm^2$ at 5 K and 8 T.