• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.434-436
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• 2000

In this study, we investigate the optical characteristics of merocyanine dye Langmuir-Blodgett(LB) film using the oscillation characteristics of quartz crystal. As results, the resistance and frequency shift at the parallel resonance under the UV irradiation is to be going down. This behaviour of resistance and frequency is different from the case of general mass adsorption into the organic film on the quartz crystal. Generally the frequency decrease of quartz crystal oscillator, which has been considered as mass loading, goes along with the resistance increase. Thus it has been suggested that the J-aggregate dissociation in merocyanine dye LB film by UV irradiation give rise to transformation of oscillation characteristics of quartz crystal.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1714-1716
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• 2000

We fabricated the optical system of merocyanine dye using Langmuir-Blodgett(LB) technique because quite uniform orientation could be obtained, which is one of the most important factors to affect to its optical characteristics. The resonance frequency and other electrical parameters at the parallel resonance state were measured using the impedance analyser(HP 4294 A). Also the morphological changes of dye molecules after UV irradiation were observed using AFM. The parallel resonance frequency and resistance by electrical equivalent circuit were decreased with the UV irradiation and these aspects are different from general mass adsorption process. Therefore the structural changes of dye molecules are being considered, that is, the aggregated molecules become dissociated. It indicates that the shifts of the resonance frequency and the others occurred without mass absorption.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.270-274
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• 2015

Molecules always show broad absorption band envelopes, and this results from the vibrational properties of bonds. The width of an absorption band can have an important influence on the color of a dye. A narrow band imparts a bright, spectrally pure color to the dye, whereas a broad band can give the same hue, but with a much duller appearance. Typically, half-band widths of cyanine dyes are about 25nm compared to value of over 50nm for typical merocyanine dyes. Thus, cyanine dyes are exceptionally bright. The factors influencing the width of an absorption band can be understood with reference to the Morse curves. The width of the absorption band depends on how closely the bond order of the molecules in the first excited state resembles that in the ground state. We have quantitatively evaluated the "molecular structure-absorption band shape" relationship of dye molecules by means of Pariser-Parr-Pople Molecular Orbital Method(PPP-MO).

• Journal of the Korean Graphic Arts Communication Society
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• v.13 no.2
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• pp.1-17
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• 1995

Organic thin film electroluminescene devices were fabricated using by molecularly doped method with N,N`-diphenyl-N,N`-bis(3-methylphenyl)-1,1`-biphenyl-4,4`-diamine(TPD) as a hole transport material, tris(8-quinolinolate) aluminium(III)(Alq3) as an emitting and electron transport agent, fluorescent squarylium(SQ) dye as a dopant, and poly(methylmethacrylate) as polymer materials. A cell structure of ITO/TPD-PMMA/Alq3-dopant/Mg was employed. The EL spectrum covers a wide range of the visible region and orange emission os observed. Two peaks at 520 and 660nm correspond to the emissions 620nm Alq3 and SQ dye, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.35-42
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• 1996

In this Paper, optical absorption were performed on LB films of binary mixtures of three kinds of merocranine dyes DO, DS, and 6Me-BS, where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly defendent on the combination of dyes. [6Me-DS]$\sub$1-x/[DOl]$\sub$x/ LB films show a sharp red shifted J-like band peak in the whole concentration range. We found the formation of f aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. Farther investigations on the present and other mixed-dye films will be needed to clarify these points.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1398-1400
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• 1998

The physical properties of the LB films with merocyanine dyes have been published and attract attention due to the possibility of molecular structure control. The evaluation of the thin films was focused for the purpose of molecular structure control. The molecular structure in the case of the thin films with dyes can be examine by optical absorption spectra measurements. In the case of optical absorption spectra of the LB films by the heat treatment at $70^{\circ}C$ in the air, both of the shifted absorption bands decay and a monomer absorption peak of about 530 nm appears instead. And, the formation and dissociation of J-aggregates, anisotropic behavior was no longer observed in the heat treated merocyanine dyes LB films. In the results, study of the merocyanine dyes LB films using optical absorption spectra would an interesting problem of absorption peak shifts and mixed components.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.128-130
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• 2001

In this study, we investigate the deposition characteristics of merocyanine dye(MD) Langmuir-Blodgett(LB) film using quartz crystal microbalance (QCM). The MD optical system mixed with fatty acid was fabricated using LB method. And their optical characteristics were investigated using UV spectroscopy. The optical behavior of MD LB film was investigated asto thermal treatment. The resonant frequency and admittance was measured during dissociation of J-aggregate of MD LB film. As a result, it has been suggested that the J-aggregate dissociation in MD LB film by thermal treatment give rise to transformation of oscillation characteristics of quartz crystal.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1569-1571
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• 1996

The role of ESR spectroscopy in the characterization of functional LB films is discussed. Optical absorption were performed on LB films of binary mixtures of three kinds of merocyanine dyes where DS and 6Me-DS form J-like aggregates but not DO in single component films. The observed optical absorption spectra of mixed films were markedly dependant on the combination of dyes. We found the formation of J-aggregates in a mixed merocyanine dyes containing a non J-aggregate forming dye DO, in a single component case. In structural studios, ESR is of particular important in the analysis of molecular orientation of LB films. Development of new functional LB films may provide more cases where ESR spectroscopy will clarify the nature of such films.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.3
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• pp.105-110
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• 2002

J-aggregates in the mutual mixing LB films of [6Me-DS]$_{1-x}$ [DO]$_{x}$,[DS]$_{1-x}$ [DO]$_{x}$ and [DSe]$_{1-x}$ [DO]$_{x}$ have been studied by optical absorption, fluorescence and surface pressure-area isotherms. In [6Me-DS]$_{1-x}$ [DO]$_{x}$ films, sharp J-band absorption and fluorescence of [6Me-DS] are linearly shifted to the longer wavelength for the replacement of [6Me-DS] by [DO]. According to the x, a smooth shift of the limited area has been cleared. In the [DS]-[DO] system, the J-band is enhanced at 1:1 composition and strong fluorescence is also observed. Also, the presence of phase separation was suggested in the [DSe]-[DO] system, because the absorption spectra were decomposed into [DSe] and [DO] spectra. On the other hand, in the pressure-area isothermal study, reduction in the molecular occupying area of monolayers has been clarified. This could be ascribed to the enhancement of molecular ordering in J-aggregates. These facts are also believed to reflect the most closely packed arrangement of chromophores in the merocyanine dye monolayers. Thus, it was confirmed that the interaction between mixed dye molecules and the CdC1$_2$+KHCO$_3$subphases affected the J-aggregates of the LB films. Also. it is thought that the J-aggregates are formed non-dimensionally in LB films, such as solution synthesized [DX:DO] assemblies on mixing.s on mixing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2245-2249
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• 2010

The physical properties of the LB films with merocyanine dyes have been published and attract attention due to the possibility of molecular structure control. The evaluation of the thin films was focused for the purpose of molecular structure control. The molecular structure in the case of the thin films with dyes can be examine by optical absorption spectra measurements. In the result measured by optical absorption spectra, the $[DX]_{1-x}[DO]_x$ LB films shows a large in-plane anisotropy and the transition dipole moment of red-shifted band is preferentially oriented perpendicular to the dipping direction of the film, while that of the blue-shifted band prefers the dipping direction. The spectrum for $0_{\circ}$, $90_{\circ}$-polarized light coincides with the spectrum for non-polarized light and also with the spectrum was observed in the LB film deposited using a fresh solution. These results show that the aging process does not cause a structural change in chromophore but a change in the degree of molecular orientation. In the results, study of the merocyanine dyes LB films using optical absorption spectra would an interesting problem of absorbance peak shifts and mixed components.