Energy deactivation pathways of porphyrins and dopa melanin in polyvinyl alcohol systems

Wróbel, Danuta; Hanyż, I.; Planner, A.; Dudkowiak, Alina; Sarna, Tadeusz

doi:10.1016/s1011-1344(98)00217-6

Cited by 14 publications

(19 citation statements)

References 19 publications

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“…In our sample no particular change in PAS shape is observed upon changing modulation frequency and signal intensity decreases as expected for monomers (not shown). Similar observation we have made for metal-free-base porphyrins [9,10,31,32] when they were in the monomeric forms. Figure 5 shows the photovoltage action spectra (the photovoltage signal versus excitation wavelength) for studied Pcs.…”

Section: Spectroscopic Studiessupporting

confidence: 86%

Spectroscopic and photoelectric studies of phthalocyanines in polyvinyl alcohol for application in solar energy conversion

Wróbel

Boguta

Ion³

2000

International Journal of Photoenergy

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Abstract. Phthalocyanines are synthetic dyes which are shown to be good photoconverters which can be applied in a photoelectrochemical cell constructed of semiconducting and metallic electrodes. By means of spectroscopic investigation (absorption, fluorescence and photoacoustics) we have followed spectral properties of phthalocyanines complexed with metals dissolved in polyvinyl alcohol solution in order to determine the pathways of deactivation of their excited states. Spectroscopic investigations were accompanied with photovoltaic/photocurrent and current-voltage characteristics of the photoelectrochemical cell with dyes. It has been shown that there is a correlation between dye fluorescence feature and dye ability to electric photoconversion. The comparison of new data for metallic phthalocyanines with those obtained for porphyrins is discussed.

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Section: Spectroscopic Studiessupporting

confidence: 86%

Spectroscopic and photoelectric studies of phthalocyanines in polyvinyl alcohol for application in solar energy conversion

Wróbel

Boguta

Ion³

2000

International Journal of Photoenergy

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“…The porphyrin dyes show a very intensive Soret band in the region of about 420 nm and less intensive Q-bands in the longwavelength region [14,20]. The absorption Soret band of TAP is shifted to the longwavelength region after mixing with dopa melanin, because TAP and dopa melanin create coulombic complex as previously shown [14][15][16]. The TPPS 4 weakly interacts with dopa melanin and does not create complex with the later one, ie.…”

Section: Resultsmentioning

confidence: 70%

“…The TPPS 4 with dopa melanin spectrum is nearly a superposition of TPPS 4 and dopa melanin spectra. The absorption spectrum of dopa melanin in PVA monotonically decreases with increasing wavelength (not shown) [14,15]. The a bsorption and photoacoustic spectra confirm that the porphyrin dyes change a part of absorbed energy into heat and show that only one form of porphyrin dye (or complex) contributes to non-radiative thermal deactivation.…”

Section: Resultsmentioning

confidence: 80%

“…The deactivation of the excited states of porphyrins as a result of fluorescence and photothermal processes was discussed [14][15][16]. The radiative and non-radiative processes which, lead to the dye molecule excited state deactivation are competitive processes with respect to charge separation.…”

Section: Introductionmentioning

confidence: 99%

“…The radiative and non-radiative processes which, lead to the dye molecule excited state deactivation are competitive processes with respect to charge separation. Therefore, photoelectric and electric measurements were accompanied with spectroscopic studies [14][15][16] to follow the fate of excitation energy.…”

Section: Introductionmentioning

confidence: 99%

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Photovoltage generation and fluorescence of charged tetraphenylporphyrins with dopa melanin

Hanyż

Wróbel²

2003

Cryst. Res. Technol.

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Positively charged tetra(4-N,N,N,N-trimethylanilinium) porphyrin (TAP) and negatively charged tetrakis(4-sulphonatophenyl) porphyrin (TPPS 4 ) and their mixtures with dopa melanin in polyvinyl alcohol have been investigated. On the basis of the absorption and fluorescence spectra it has been established the formation of TAP-dopa melanin complex which fluorescence is quenched whereas TPPS 4 fluorescence behaviour is only slightly changed in the presence of dopa melanin. Photovoltaic effects and photocurrent generation in a photoelectrochemical cell consisting of a layer dye solutions sandwiched between the semiconducting and gold electrodes have been investigated. The dependence of photovoltage signal on excitation wavelength (photovoltage action spectrum), kinetics of photocurrent rise and decay in the second time scale have been presented. Electric parameters of the photoelectrochemical cell (conductivity and capacitance) with porphyrin dyes, dopa melanin and their mixtures in the dark and upon illumination have been estimated. It was shown that all investigated dyes are able to generate photosignal but the values of photocurrent generated depend on the dye used in the experiment and the presence or absence of dopa melanin.

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Nanostructured Al0.2Y1.8O3 semiconductor assisted enhancement in PVOH fortitude to withstand high energy UV photons: An opto-mechanical study

Jagajeevanraj¹,

Sachhidananda

Pushpalatha³

et al. 2019

Optik

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Energy deactivation pathways of porphyrins and dopa melanin in polyvinyl alcohol systems

Cited by 14 publications

References 19 publications

Spectroscopic and photoelectric studies of phthalocyanines in polyvinyl alcohol for application in solar energy conversion

Spectroscopic and photoelectric studies of phthalocyanines in polyvinyl alcohol for application in solar energy conversion

Photovoltage generation and fluorescence of charged tetraphenylporphyrins with dopa melanin

Nanostructured Al0.2Y1.8O3 semiconductor assisted enhancement in PVOH fortitude to withstand high energy UV photons: An opto-mechanical study

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