ABSTRACT A series of six conjugated aromatic polyazomethines has been obtained by high-temperatur... more ABSTRACT A series of six conjugated aromatic polyazomethines has been obtained by high-temperature solution polycondensation of diformyltriphenylamine with different primary aromatic diamines. The structures of polymers are characterized by means FTIR, 1H NMR, and 13C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. Polyazomethines emitted blue or blue-green light. Relative PL intensity of the polymers investigated in chloroform solution was found about 0.30%, while for doped ones it was about 20% in relation to 9,10-diphenylanthracene. Additionally, the photoluminescence spectra of the polyazomethines in polymer blend with poly(methyl methacrylate) (PMMA) have also been described. The lowest optical band gap value at 2.41 eV was detected. Polymers were investigated also by cyclic voltametry and differential pulse voltammetry in dichloromethane. An influence of different types of dopants, i.e., methanesulfonic acid (MSA), camphorsulfonic acid (CSA), m-cresol (MC), p-chlorophenol (PC), and p-pentadecylphenol (PDP), on absorption and emission wavelengths was investigated.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Optical (UV-vis and photoluminescence) properties of two soluble organic molecules based on azome... more Optical (UV-vis and photoluminescence) properties of two soluble organic molecules based on azomethines with benzothiazole core (BTA1 and BTA2) were reported. The structures of both compounds are characterized by means FTIR, (1)H NMR, and (13)C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. The investigated compounds emitted blue light. Influence of excitation wavelength and concentration on maximum and intensity of emission of BTA1 and BTA2 was found. Electrochemical properties of the compounds were studied by differential pulse voltammetry. Introduction of fluorine moieties (BTA1) resulted in lower energy band gap (E(g)) of approximately ∼0.5 eV, whereas BTA2 showed E(g) of ∼2.8 eV. The devices comprised of BTA1 with P3HT:PCBM (1:1:1) showed an open circuit voltage (V(OC)) of 0.40 V, a short circuit current (J(SC)) of 1.19 mA/cm(2), and a fill factor (FF) of 0.23, giving a power-conversion efficiency (PCE) of 0.10% under AM1.5 G irradiation (100 mW/cm(2)).
Tuning the chemical structure, band gap of conjugated polymers and designing LEDs emitting select... more Tuning the chemical structure, band gap of conjugated polymers and designing LEDs emitting selected colors remains a challenging issue. In our work three strategies were reported for tuning the emission color of aromatic polyimides: (i) changing the main chain molecular structure, (ii) blending a light emitting polymer with another nonemissive polymer such as poly(methylmethacrylate) (PMMA) and (iii) doping. Additionally, in this paper we present the effect of excitation wavelength, concentration, film thickness and kind of solvent on the photoluminescence (PL) properties of the polyimides. New conjugated polyimides, i.e. polymers containing cyclic imide and aromatic groups in the main chain, were synthesized from four different diamines and five different dianhydrides via polycondensation with the goal to obtain new materials with tunable luminescent properties. The following commercial diamines 2,7-diaminofluorene (DAF), 2,4-diamino-6-phenyl-1,3,5-triazine (DAPT), 4,4'-methyle...
We investigated optical, electrical and mechanical properties of indium tin oxide (ITO) on flexib... more We investigated optical, electrical and mechanical properties of indium tin oxide (ITO) on flexible polyethylene terephthalate (PET) substrate, considering bulk-heterojunction (BHJ) polymer solar cells applications. Encapsulation of flexible solar cells with the architecture PET/ITO/PEDOT:PSS/P3HT:PCBM (or P3HT:PCBM:AZ-NDI-4)/Al was done by direct brush-painting with nail enamel. Active cell layer blends of [6,6]-phenyl C61 butyric acid methyl ester (PCBM) with regioregular or regiorandom poly(3-hexylthiophene-2,5-diyl) (P3HT) were applied. Additionally for this role the mixture of regioregular P3HT:PCBM with naphthalene diimide–imine with four thiophene rings AZ-NDI-4 was tested. Obtained photovoltaic (PV) and optical (UV–vis) results of the flexible polymer solar cells were compared with the same architecture of devices on the glass/ITO substrate.
ABSTRACT A series of six conjugated aromatic polyazomethines has been obtained by high-temperatur... more ABSTRACT A series of six conjugated aromatic polyazomethines has been obtained by high-temperature solution polycondensation of diformyltriphenylamine with different primary aromatic diamines. The structures of polymers are characterized by means FTIR, 1H NMR, and 13C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. Polyazomethines emitted blue or blue-green light. Relative PL intensity of the polymers investigated in chloroform solution was found about 0.30%, while for doped ones it was about 20% in relation to 9,10-diphenylanthracene. Additionally, the photoluminescence spectra of the polyazomethines in polymer blend with poly(methyl methacrylate) (PMMA) have also been described. The lowest optical band gap value at 2.41 eV was detected. Polymers were investigated also by cyclic voltametry and differential pulse voltammetry in dichloromethane. An influence of different types of dopants, i.e., methanesulfonic acid (MSA), camphorsulfonic acid (CSA), m-cresol (MC), p-chlorophenol (PC), and p-pentadecylphenol (PDP), on absorption and emission wavelengths was investigated.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
Optical (UV-vis and photoluminescence) properties of two soluble organic molecules based on azome... more Optical (UV-vis and photoluminescence) properties of two soluble organic molecules based on azomethines with benzothiazole core (BTA1 and BTA2) were reported. The structures of both compounds are characterized by means FTIR, (1)H NMR, and (13)C NMR spectroscopy and elemental analysis; the results show an agreement with the proposed structure. The investigated compounds emitted blue light. Influence of excitation wavelength and concentration on maximum and intensity of emission of BTA1 and BTA2 was found. Electrochemical properties of the compounds were studied by differential pulse voltammetry. Introduction of fluorine moieties (BTA1) resulted in lower energy band gap (E(g)) of approximately ∼0.5 eV, whereas BTA2 showed E(g) of ∼2.8 eV. The devices comprised of BTA1 with P3HT:PCBM (1:1:1) showed an open circuit voltage (V(OC)) of 0.40 V, a short circuit current (J(SC)) of 1.19 mA/cm(2), and a fill factor (FF) of 0.23, giving a power-conversion efficiency (PCE) of 0.10% under AM1.5 G irradiation (100 mW/cm(2)).
Tuning the chemical structure, band gap of conjugated polymers and designing LEDs emitting select... more Tuning the chemical structure, band gap of conjugated polymers and designing LEDs emitting selected colors remains a challenging issue. In our work three strategies were reported for tuning the emission color of aromatic polyimides: (i) changing the main chain molecular structure, (ii) blending a light emitting polymer with another nonemissive polymer such as poly(methylmethacrylate) (PMMA) and (iii) doping. Additionally, in this paper we present the effect of excitation wavelength, concentration, film thickness and kind of solvent on the photoluminescence (PL) properties of the polyimides. New conjugated polyimides, i.e. polymers containing cyclic imide and aromatic groups in the main chain, were synthesized from four different diamines and five different dianhydrides via polycondensation with the goal to obtain new materials with tunable luminescent properties. The following commercial diamines 2,7-diaminofluorene (DAF), 2,4-diamino-6-phenyl-1,3,5-triazine (DAPT), 4,4'-methyle...
We investigated optical, electrical and mechanical properties of indium tin oxide (ITO) on flexib... more We investigated optical, electrical and mechanical properties of indium tin oxide (ITO) on flexible polyethylene terephthalate (PET) substrate, considering bulk-heterojunction (BHJ) polymer solar cells applications. Encapsulation of flexible solar cells with the architecture PET/ITO/PEDOT:PSS/P3HT:PCBM (or P3HT:PCBM:AZ-NDI-4)/Al was done by direct brush-painting with nail enamel. Active cell layer blends of [6,6]-phenyl C61 butyric acid methyl ester (PCBM) with regioregular or regiorandom poly(3-hexylthiophene-2,5-diyl) (P3HT) were applied. Additionally for this role the mixture of regioregular P3HT:PCBM with naphthalene diimide–imine with four thiophene rings AZ-NDI-4 was tested. Obtained photovoltaic (PV) and optical (UV–vis) results of the flexible polymer solar cells were compared with the same architecture of devices on the glass/ITO substrate.
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