• E2M - 전기 전자와 첨단 소재
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• 제8권4호
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• pp.406-412
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• 1995

A n-CdS thin films were evaporated by thermal evaporation method and their structure, optical transmission spectra and electrical characteristics were investigated. The photovoltaic characteristics of solar cells which were fabricated in optimum conditions measured. The evaporated CdS thin films showed in hexagonal structure and above 80% of optical transmission spectra regardless of impurity doping. The high quality thin films could be obtained at 150.deg. C temperature of substrate, which is useful for solar cell window layer with low resistivity of 6*10$\^$-2/(.ohm.-cm) by In doping We measured the electrical and optical characteristics of the n-CdS/p-InP heterojunction solar cells. The most efficient photovoltaic characteristics of heterojunction solar cells had the open circuit voltage of 0.66V, short circuit current density of 13.85mA/cm$\^$2/, fill factor of 0.576 and conversion efficiency of 8.78% under 60mW/cm$\^$2/ illumination.

• 대한화학회지
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• 제43권1호
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• pp.1-7
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• 1999

이 논문에서는 광화학적 방법을 이용하여 금속 콜로이드 입자를 반도체 나노입자를 함유한 수용액내에서 제조하여 그 광학적 특성을 관찰하였다. 형성된 금속입자는 사용된 반도체 입자에 따라 다른 경향을 나타낸다. Au 금속 입자를 CdS 입자를 함유한 수용액내에서 제조한 경우 일반적인 금속 입자의 Plasmon Resonance의 특성을 보이는 반면 Ag금속 입자를 AgBr 입자를 함유한 용액내에서 제조한 경우 Red-Shift 현상을 보였고, 그 정도는 UV 조사량에 따라 달라졌다. 이러한 금속 Plasmon Resonance의 Red-Shift 현상을 Effective Medium 이론을 이용하여 이론적으로 설명하였다.

• 한국환경과학회지
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• 제7권1호
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• pp.62-66
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• 1998

Toxic Mastoparan B(MP-B) which is purified from the venom of the hornet Vespa basalis is a cationic amphlphilic tetradecapeptide. MP-B and Its Ala-substituted analogues were synthesized by solld phase method and the toxic peptide-membrane interactions were examined by circular dichroism(CD) spectra, fluorescence spectra, and leakage abilities in phospholipid membranes. In the presence of phospholipid vesicles, synthetic MP-B and its analogues formed amphiphilic -helical structures, but in the buffer soletion, those exhibited random coil conformation as measured by CD. Fluorescence spectra of MP-B and its analogues which indicated the binding affinity of peptide on phospholipid vesicles showed that the replacement of Lys at position 2 and 11 with Ala caused a remarkable effect in the blue shalt and that at position 2, in the leakage ability of the peptide.

• 한국광학회지
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• 제6권2호
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• pp.165-171
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• 1995

Infrared-Radio frequency double resonance (IRRFDR) and Infrared-Microwave double resonance (IRMWDR) spectroscopy have been used to probe a level of A symmetry for $CD_{3}$OH. Double resonance spectra of $CD_{3}$OH have been investigated over the range of 940 to 1020 $cm ^{-1}$ . Twenty K-type doublet transitions have been observed in both the radio frequency region, which covers 50 MHz to 1 GHz, and the microwave region, which covers 8 GHz to 12 GHz. The results propose new assignments of infrared (IR) absorption transitions and far-infrared (FIR) laser emission lines. These involve torsional excited levels and CO stretch states. Measurements of the A state splitting have permitted the determination of the asymmetry splitting parameters $S^{o}$(n, K) and $^{co}$ (n, K) for (n, K)=(0.3) and (1.3)

• 한국진공학회지
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• 제1권1호
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• pp.50-59
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• 1992

X선 광전자 분광방법(XPS)에 의하여 CdTe의 절개된 (110) 표면과 스퍼터링된 표 면을 산소에 노출시키면서 CdTe 표면의 산화과정의 초기단계에 대하여 고찰하였다. Te 3d5/2, Cd 3d5/2, O 1s, Cd MNN 오제 스펙트럼 등의 분석으로부터 산화의 초기단계에서 산 소원자 두 개가 Te 원자 한 개에 결합하고 있음을 보았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.195-197
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• 2002

CdTe quantum dots(QDs) were synthesized in aqueous solution by colloidal method. Photoluminescence(PL) spectra of the synthesized CdTe QDs revealed the intensity of PL peaks was stronger as the condensation time was longer. This result was thought because annealing effect by thermal energy transferred during condensation eliminated defects which act as traps and recombination centers in CdTe particle. PL intensity has stron dependence of Te precursor concentration. It confirmed the ratio of Te ion to Cd ion added during synthesis affected the particle size and size distribution of the CdTe QDs. Finally, the synthesized CdTe QDs were identified to be cubic structured CdTe quantum dots by X-ray diffraction(XRD).

• Bulletin of the Korean Chemical Society
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• 제17권11호
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• pp.1052-1056
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• 1996

The effects of β-CD, Me-β-CD, and biphenyl capped β-CD on 1H NMR spectra of mandelic acid 1, α-methylbenzylamine 2 and 2-phenylpropionic acid 3 were investigated. Enantiomeric recognition was observed for mandelic acid 1 by all the hosts used, for α-methylbenzylamine 2 by β-CD and Me-β-CD, and for 2-phenylpropionic acid 3 by Me-β-CD. In the presence of biphenyl-capped β-CD, ο-, m-, and p-protons of the phenyl groups of the guests are discriminated due to ring current of the capped biphenyl group. The splitting pattern of the phenyl protons indicates that the phenyl group of the guests is inserted into the β-CD cavity from the secondary hydroxyl side and positioned in close proximity to the capped biphenyl ring. The magnitude of the upfield shifts of H3 and H5 protons of β-CD upon binding of guests 1-3 is similar to that caused by ephedrine or pseudoephedrine, suggesting that the substitution at benzylic carbon atom has little effect on the depth of the insertion of the phenyl group into the β-CD cavity and stability of the inclusion complexes.

• 한국자기공명학회논문지
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• 제20권4호
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• pp.109-113
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• 2016

Resonance frequencies from the $^{113}Cd$ and $^{133}Cs$ nuclear magnetic resonance (NMR) spectra for the $CsCdBr_3$ single crystal were measured at varying temperatures by the static NMR method. The temperature-dependent changes of these frequencies are related to the changing structural geometry of the ${CdBr_6}^{4-}$ units, which affects the environment of $^{133}Cs$. The spin-lattice relaxation rates ($1/T_1$) for the $^{113}Cd$ and $^{133}Cs$ nuclei were measured in order to obtain detailed information about the dynamics of $CsCdBr_3$ crystals. The dominant relaxation mechanisms for $^{113}Cd$ and $^{133}Cs$ nuclei are direct single-phonon and Raman spin-phonon processes, respectively.

• 한국결정학회지
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• 제19권1호
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• pp.25-30
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• 2008

In order to characterize the optical properties of CdS thin films and CdS powders, the following experiments were performed: CdS wurtzite thin films were made using 99.99% CdS (Aldrich) powder and the $AlO_x$ membranes in $7{\times}10^{-6}$ torr(here, the average vacuum coating speed is $1{\AA}/sec$.). The surface states of CdS nano-particles with dimensions of 3.87 nm were studied through the fluorescence spectroscopy. From the resulting spectra exhibited, we can see a sharp fluorescence at 451 nm arising from the excitons on the CdS thin films, compared with the 448nm peak of the CdS powders.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.30-41
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• 2002

The neutron beam is fully characterized for the prompt gamma activation analysis facility at Hanaro in the Korea Atomic Energy Research Institute(KAERI). The facility uses thermal neutrons which are diffracted vertically from a horizontal beam port by a set of pyrolytic graphite(PG) crystals positioned at the Bragg angle of 45" Neutron spectra, neutron flux and Cd-ratio are determined for the three extraction modes of diffracted beam by means of the theoretical and experimental efforts. To obtain theoretical result, the reflectivity of pyrolytic graphite is calculated in the diffraction model for mosaic crystal and the angular divergence after diffraction by mosaic crystal is estimated from Monte Carlo simulation. The time-of-flight spectrometer and gold activation wire are used for measuring the neutron spectra. Both the calculated and measured spectra have proven that the unique feature of polychromatic beam obtained by PG crystals are useful for PGAA. The thermal neutron flux of 7.9$\times$107 n/cm$^2$s and the Cd-ratio of 266 for gold have been achieved at the sample position while the reactor operates at 24 MW The uniformity of beam flux is 12% in the central 1$\times$1 cm$^2$ area. Finally, the beam is briefly characterized by the effective velocity and temperature which are determined by measuring the prompt Y-ray spectra for thin and thick boron samples.ples.