scholarly journals Optical, Electrochemical, Thermal, and Structural Properties of Synthesized Fluorene/Dibenzosilole-Benzothiadiazole Dicarboxylic Imide Alternating Organic Copolymers for Photovoltaic Applications

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1147 ◽  
Author(s):  
Ary R. Murad ◽  
A. Iraqi ◽  
Shujahadeen B. Aziz ◽  
Sozan N. Abdullah ◽  
Rebar T. Abdulwahid ◽  
...  
Keyword(s):  
Structural Properties ◽  
Energy Levels ◽  
Average Molecular Weight ◽  
Excellent Thermal Stability ◽  
Alkyl Chains ◽  
Molecular Weights ◽  
Photovoltaic Applications ◽  
Amorphous Nature ◽  
Donor Acceptor ◽  
The Impact

In this work, four donor–acceptor copolymers, PFDTBTDI-DMO, PFDTBTDI-8, PDBSDTBTDI-DMO, and PDBSDTBTDI-8, based on alternating 2,7-fluorene or 2,7-dibenzosilole flanked by thienyl units, as electron-donor moieties and benzothiadiazole dicarboxylic imide (BTDI) as electron-accepting units, have been designed and synthesized for photovoltaic applications. All polymers were synthesized in good yields via Suzuki polymerization. The impact of attaching two different alkyl chains (3,7-dimethyloctyl vs. n-octyl) to the BTDI units upon the solubilities, molecular weights, optical and electrochemical properties, and thermal and structural properties of the resulting polymers was investigated. PFDTBTDI-8 has the highest number average molecular weight (Mn = 24,900 g·mol−1) among all polymers prepared. Dibenzosilole-based polymers have slightly lower optical band gaps relative to their fluorene-based analogues. All polymers displayed deep-lying HOMO levels. Their HOMO energy levels are unaffected by the nature of either the alkyl substituents or the donor moieties. Similarly, the LUMO levels are almost identical for all polymers. All polymers exhibit excellent thermal stability with Td exceeding 350 °C. X-ray powder diffraction (XRD) studies have shown that all polymers have an amorphous nature in the solid state.

scholarly journals Fabrication of Alternating Copolymers Based on Cyclopentadithiophene-Benzothiadiazole Dicarboxylic Imide with Reduced Optical Band Gap: Synthesis, Optical, Electrochemical, Thermal, and Structural Properties

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 63
Author(s):  
Ary R. Murad ◽  
Ahmed Iraqi ◽  
Shujahadeen B. Aziz ◽  
Sozan N. Abdullah ◽  
Mohamad A. Brza ◽  
...  
Keyword(s):  
Structural Properties ◽  
Molecular Orbital ◽  
Average Molecular Weight ◽  
Good Thermal Stability ◽  
Molecular Weights ◽  
Alternating Copolymers ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Direct Arylation Polymerization ◽  
The Impact

A series of alternating copolymers containing cyclopentadithiophene (CPDT) flanked by thienyl moieties as electron-donor units and benzothiadiazole dicarboxylic imide (BTDI) as electron-acceptor units were designed and synthesized for solar cell applications. Different solubilizing side chains, including 2-ethylhexyl chains and n-octyl chains were attached to CPDT units, whereas 3,7-dimethyloctyl chains and n-octyl chains were anchored to the BTDI moieties. The impact of these substituents on the solubilities, molecular weights, optical and electrochemical properties, and thermal and structural properties of the resulting polymers was investigated. PCPDTDTBTDI-EH, DMO was synthesized via Suzuki polymerization, whereas PCPDTDTBTDI-8, DMO, and PCPDTDTBTDI-EH, 8 were prepared through direct arylation polymerization. PCPDTDTBTDI-8, DMO has the highest number average molecular weight (Mn = 17,400 g mol−1) among all polymers prepared. The PCPDTDTBTDI-8, DMO and PCPDTDTBTDI-8, 8 which have n-octyl substituents on their CPDT units have comparable optical band gaps (Eg ~ 1.3 eV), which are around 0.1 eV lower than PCPDTDTBTDI-EH, DMO analogues that have 2-ethylhexyl substituents on their CPDT units. The polymers have their HOMO levels between −5.10 and −5.22 eV with PCPDTDTBTDI-EH, DMO having the deepest highest occupied molecular orbital (HOMO) energy level. The lowest unoccupied molecular orbital (LUMO) levels of the polymers are between −3.4 and −3.5 eV. All polymers exhibit good thermal stability with decomposition temperatures surpassing 350 °C. Powder X-ray diffraction (XRD) studies have shown that all polymers have the amorphous nature in solid state.

scholarly journals Characteristics of Low Band Gap Copolymers Containing Anthracene-Benzothiadiazole Dicarboxylic Imide: Synthesis, Optical, Electrochemical, Thermal and Structural Studies

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 62
Author(s):  
Ary R. Murad ◽  
Ahmed Iraqi ◽  
Shujahadeen B. Aziz ◽  
Mohammed S. Almeataq ◽  
Sozan N. Abdullah ◽  
...  
Keyword(s):  
Band Gap ◽  
Molecular Orbital ◽  
Energy Levels ◽  
X Ray Diffraction ◽  
Low Band Gap ◽  
Molecular Weights ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital ◽  
The Impact

Two novel low band gap donor–acceptor (D–A) copolymers, poly[9,10-bis(4-(dodecyloxy)phenyl)-2,6-anthracene-alt-5,5-(4′,7′-bis(2-thienyl)-2′,1′,3′-benzothiadiazole-N-5,6-(3,7-dimethyloctyl)dicarboxylic imide)] (PPADTBTDI-DMO) and poly[9,10-bis(4-(dodecyloxy)phenyl)-2,6-anthracene-alt-5,5-(4′,7′-bis(2-thienyl)-2′,1′,3′-benzothiadiazole-5,6-N-octyl-dicarboxylic imide)] (PPADTBTDI-8) were synthesized in the present work by copolymerising the bis-boronate ester of 9,10-phenylsubstituted anthracene flanked by thienyl groups as electron–donor units with benzothiadiazole dicarboxylic imide (BTDI) as electron–acceptor units. Both polymers were synthesized in good yields via Suzuki polymerisation. Two different solubilizing alkyl chains were anchored to the BTDI units in order to investigate the impact upon their solubilities, molecular weights, optical and electrochemical properties, structural properties and thermal stability of the resulting polymers. Both polymers have comparable molecular weights and have a low optical band gap (Eg) of 1.66 eV. The polymers have low-lying highest occupied molecular orbital (HOMO) levels of about −5.5 eV as well as the similar lowest unoccupied molecular orbital (LUMO) energy levels of −3.56 eV. Thermogravimetric analyses (TGA) of PPADTBTDI-DMO and PPADTBTDI-8 did not prove instability with decomposition temperatures at 354 and 313 °C, respectively. Powder X-ray diffraction (XRD) studies have shown that both polymers have an amorphous nature in the solid state, which could be used as electrolytes in optoelectronic devices.

Optical and Electrochemical Properties of a New Donor-Acceptor Type Conjugated Polymer Derived from Thiophene, Carbazole and 1,3,4-Oxadiazole Units

2010 ◽  
Vol 657 ◽  
pp. 46-55
Author(s):  
M.G. Manjunatha ◽  
Airody Vasudeva Adhikari ◽  
Pramod Kumar Hegde
Keyword(s):  
Energy Levels ◽  
Average Molecular Weight ◽  
Green Fluorescence ◽  
Weight Average Molecular Weight ◽  
Cyclic Voltammetric ◽  
Light Emitting ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Polymer Light Emitting Diodes ◽  
Multistep Reactions

A new donor-acceptor type poly[3-{5-[3,4-didecyloxy-5-(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-1,3,4-oxadiazol-2-yl}-9-dodecyl-9H-carbazole] (P) has been synthesized starting from thiodiglycolic acid and 9H-carbazole through multistep reactions. The polymer has been synthesized through precursor polyhydrazide route. The weight average molecular weight of the polymer was found to be 7210. The polymer exhibited intense green fluorescence in solid sate. Cyclic voltammetric experiments showed that the polymer has low-lying LUMO (-3.55 eV) and high lying HOMO (-5.77 eV) energy levels due to the presence of alternate donor and acceptor units. The optical and electrochemical studies reveal that the new polymer (P) is a promising material for the development of polymer light emitting diodes (PLEDs).

scholarly journals Influence of Fluorine Substitution on the Optical, Thermal, Electrochemical and Structural Properties of Carbazole-Benzothiadiazole Dicarboxylic Imide Alternate Copolymers

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2910 ◽  
Author(s):  
Ary R. Murad ◽  
Ahmed Iraqi ◽  
Shujahadeen B. Aziz ◽  
Hunan Hi ◽  
Sozan N. Abdullah ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Orbital ◽  
Energy Levels ◽  
Average Molecular Weight ◽  
Band Gaps ◽  
Hydrogen Atoms ◽  
Good Thermal Stability ◽  
Optical Band Gaps ◽  
Fluorinated Copolymers ◽  
The Impact

In this work four novel donor-acceptor copolymers, PCDTBTDI-DMO, PCDTBTDI-8, P2F-CDTBTDI-DMO and P2F-CDTBTDI-8, were designed and synthesised via Suzuki polymerisation. The first two copolymers consist of 2,7-carbazole flanked by thienyl moieties as the electron donor unit and benzothiadiazole dicarboxylic imide (BTDI) as electron acceptor units. In the structures of P2F-CDTBTDI-DMO and P2F-CDTBTDI-8 copolymers, two fluorine atoms were incorporated at 3,6-positions of 2,7-carbazole to investigate the impact of fluorine upon the optoelectronic, structural and thermal properties of the resulting polymers. P2F-CDTBTDI-8 possesses the highest number average molecular weight (Mn = 24,200 g mol−1) among all the polymers synthesised. PCDTBTDI-DMO and PCDTBTDI-8 show identical optical band gaps of 1.76 eV. However, the optical band gaps of fluorinated copolymers are slightly higher than non-fluorinated counterparts. All polymers have deep-lying highest occupied molecular orbital (HOMO) levels. Changing the alkyl chain substituents on BTDI moieties from linear n-octyl to branched 3,7-dimethyloctyl groups as well as substituting the two hydrogen atoms at 3,6-positions of carbazole unit by fluorine atoms has negligible impact on the HOMO levels of the polymers. Similarly, the lowest unoccupied molecular orbital (LUMO) energy levels are almost comparable for all polymers. Thermogravimetric analysis (TGA) has shown that all polymers have good thermal stability and also confirmed that the fluorinated copolymers have higher thermal stability relative to those non-fluorinated analogues. Powder X-ray diffraction (XRD) studies proved that all polymers have an amorphous nature in the solid state.

scholarly journals Understanding Electrodeposition of Chitosan–Hydroxyapatite Structures for Regeneration of Tubular-Shaped Tissues and Organs

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1288
Author(s):  
Katarzyna Nawrotek ◽  
Jacek Grams
Keyword(s):  
Structural Properties ◽  
Secondary Ion Mass Spectrometry ◽  
Average Molecular Weight ◽  
Initial Concentration ◽  
Cathodic Electrodeposition ◽  
Deacetylation Degree ◽  
Fundamental Information ◽  
The Impact ◽  
Secondary Ion ◽  
Scanning Electron

Tubular-shaped hydrogel structures were obtained in the process of cathodic electrodeposition from a chitosan–hydroxyapatite solution carried out in a cylindrical geometry. The impact of the initial concentration of solution components (i.e., chitosan, hydroxyapatite, and lactic acid) and process parameters (i.e., time and voltage) on the mass and structural properties of deposit was examined. Commercially available chitosan differs in average molecular weight and deacetylation degree; therefore, these parameters were also studied. The application of Fourier-transform infrared spectroscopy, scanning electron microscopy, and time-of-flight secondary ion mass spectrometry allowed obtaining fundamental information about the type of bonds and interactions created in electrodeposited structures. Biocompatible tubular implants are highly desired in the field of regeneration or replacement of tubular-shaped tissues and organs; therefore, the possibility of obtaining deposits with the desired structural properties is highly anticipated.

scholarly journals Resolving Donor-Acceptor Interfaces and Charge Carrier Energy Levels of Organic Semiconductors with Polar Side Chains

2020 ◽  
Author(s):  
Riccardo Alessandri ◽  
Selim Sami ◽  
Jonathan Barnoud ◽  
Alex H. de Vries ◽  
Siewert-Jan Marrink ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Organic Semiconductors ◽  
Large Scale ◽  
Energy Levels ◽  
Acid Methyl Ester ◽  
Side Chains ◽  
Organic Thin Film ◽  
Carrier Energy ◽  
Donor Acceptor ◽  
The Impact

<div> <div> <div> <p>Organic semiconductors consisting of molecules bearing polar side chains have been proposed as potential candidates to overcome the limitations of organic photovoltaics owing to their enhanced dielectric constant. However, introducing such polar molecules in photovoltaic devices has not yet resulted in higher efficiencies. A microscopic understanding of the impact of polar side chains on electronic and structural properties of organic semiconductors is paramount to rationalize their effect. Here, we investigate the impact of such side chains on bulk heterojunction overall morphology, molecular configurations at donor-acceptor (DA) interfaces, and charge carrier energy levels. The multiscale modeling approach used allows to resolve DA interfaces with atomistic resolution while taking into account the large-scale self-organization process which takes place during the processing of an organic thin film. The polar fullerene-based blends are compared to the well-studied reference system, poly(3-hexyl-thiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM). Introduction of polar side chains on a similar molecular scaffold does not affect molecular orientations at the DA interfaces; such orientations are however found to be affected by processing conditions and polymer molecular weight. Polar side chains, instead, are found to impact considerably the charge carrier energy levels of the organic blend, causing electrostatic-induced broadening of these levels. </p> </div> </div> </div>

scholarly journals Revisiting the Charge-Transfer States at Pentacene/C60 Interfaces with the GW/Bethe–Salpeter Equation Approach

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2728
Author(s):  
Takatoshi Fujita ◽  
Yoshifumi Noguchi ◽  
Takeo Hoshi
Keyword(s):  
Charge Transfer ◽  
Energy Levels ◽  
Absorption Peak ◽  
Model Systems ◽  
Equation Approach ◽  
Charge Delocalization ◽  
The Face ◽  
Donor Acceptor ◽  
The Impact ◽  
Main Absorption Peak

Molecular orientations and interfacial morphologies have critical effects on the electronic states of donor/acceptor interfaces and thus on the performance of organic photovoltaic devices. In this study, we explore the energy levels and charge-transfer states at the organic donor/acceptor interfaces on the basis of the fragment-based GW and Bethe–Salpeter equation approach. The face-on and edge-on orientations of pentacene/C60 bilayer heterojunctions have employed as model systems. GW+Bethe–Salpeter equation calculations were performed for the local interface structures in the face-on and edge-on bilayer heterojunctions, which contain approximately 2000 atoms. Calculated energy levels and charge-transfer state absorption spectra are in reasonable agreements with those obtained from experimental measurements. We found that the dependence of the energy levels on interfacial morphology is predominantly determined by the electrostatic contribution of polarization energy, while the effects of induction contribution in the edge-on interface are similar to those in the face-on. Moreover, the delocalized charge-transfer states contribute to the main absorption peak in the edge-on interface, while the face-on interface features relatively localized charge-transfer states in the main absorption peak. The impact of the interfacial morphologies on the polarization and charge delocalization effects is analyzed in detail.

scholarly journals Synthesis, Optical, Thermal and Structural Characteristics of Novel Thermocleavable Polymers Based on Phthalate Esters

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2791 ◽  
Author(s):  
Ary R. Murad ◽  
A. Iraqi ◽  
Shujahadeen B. Aziz ◽  
Sozan N. Abdullah ◽  
Rebar T. Abdulwahid
Keyword(s):  
Electron Donor ◽  
Electron Acceptor ◽  
Structural Characteristics ◽  
Phthalate Esters ◽  
Average Molecular Weight ◽  
Phthalate Ester ◽  
Energy Devices ◽  
Molecular Weights ◽  
Significant Control ◽  
The Impact

In this work three novel phthalate-based thermocleavable copolymers, PBTP-11, PBTDTP-11 and PFDTP-11 have been designed and synthesized. PBTP-11 and PBTDTP-11 were prepared by copolymerizing distannylated bithiophene without or with flanked thienyl groups as the electron-donor units with dibrominated secondary phthalate ester as the electron-acceptor units. PFDTP-11 was prepared by copolymerizing distannylated fluorene flanked by thienyl groups as the electron-donor moieties with dibrominated secondary phthalate ester as the electron-acceptor moieties. All polymers were prepared via the Stille polymerization. The impact of two different electron-donor units on the solubility, molecular weights, optical properties, thermal and structural properties of the resulting polymers were investigated. PFDTP-11 had the highest average molecular weight (Mn = 16,400 g mol−1). The polymers had Eg in the range of 2.11–2.58 eV. After thermal treatment, the Eg of the polymers were reduced by around 0.3–0.4 eV. This significant control over bandgap is promising and opens a gate towards commercializing these copolymers in energy harvesting devices such as solar cells. TGA data showed weight loss at around 300 °C, corresponding to the elimination of the secondary ester groups. After annealing, the soluble precursor polymers were transformed into active phthalic anhydride polymers and the resulting films were completely insoluble in all solvents, which shows good stability. Powder XRD studies showed that all polymers have an amorphous nature in the solid state, and therefore can be employed as electrolytes in energy devices.

scholarly journals Resolving Donor-Acceptor Interfaces and Charge Carrier Energy Levels of Organic Semiconductors with Polar Side Chains

2020 ◽  
Author(s):  
Riccardo Alessandri ◽  
Selim Sami ◽  
Jonathan Barnoud ◽  
Alex H. de Vries ◽  
Siewert-Jan Marrink ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Organic Semiconductors ◽  
Large Scale ◽  
Energy Levels ◽  
Acid Methyl Ester ◽  
Side Chains ◽  
Organic Thin Film ◽  
Carrier Energy ◽  
Donor Acceptor ◽  
The Impact

<div> <div> <div> <p>Organic semiconductors consisting of molecules bearing polar side chains have been proposed as potential candidates to overcome the limitations of organic photovoltaics owing to their enhanced dielectric constant. However, introducing such polar molecules in photovoltaic devices has not yet resulted in higher efficiencies. A microscopic understanding of the impact of polar side chains on electronic and structural properties of organic semiconductors is paramount to rationalize their effect. Here, we investigate the impact of such side chains on bulk heterojunction overall morphology, molecular configurations at donor-acceptor (DA) interfaces, and charge carrier energy levels. The multiscale modeling approach used allows to resolve DA interfaces with atomistic resolution while taking into account the large-scale self-organization process which takes place during the processing of an organic thin film. The polar fullerene-based blends are compared to the well-studied reference system, poly(3-hexyl-thiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM). Introduction of polar side chains on a similar molecular scaffold does not affect molecular orientations at the DA interfaces; such orientations are however found to be affected by processing conditions and polymer molecular weight. Polar side chains, instead, are found to impact considerably the charge carrier energy levels of the organic blend, causing electrostatic-induced broadening of these levels. </p> </div> </div> </div>

scholarly journals Synthesis and Characterization of Fluorene-Based Polymers Having Azine Unit for Blue Light Emission

2015 ◽  
Vol 62 ◽  
pp. 21-28
Author(s):  
Zhong Min Geng ◽  
Masashi Kijima
Keyword(s):  
Molecular Orbital ◽  
Light Emission ◽  
Energy Levels ◽  
Average Molecular Weight ◽  
Orbital Energy ◽  
Good Thermal Stability ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital

Two types of donor-acceptor copolymers were designed and synthesized by combination of an electron donor unit of fluorene sequences and an electron acceptor azine unit such as 1,2,4,5-tetrazine and 1,3,5-triazine. They were well soluble in common organic solvents with the number average molecular weight (Mn) of 7.0 and 14.5 kg mol-1, respectively, and have good thermal stability showing about at 360 °C with 5 wt% loss in TGA. Two copolymers exhibited intense blue photoluminescence with emission peak maxima at 437 and 421 nm in CHCl3, and 451 and 422 nm in the film state, respectively. These polymers exhibited good fluorescence quantum efficiencies in CHCl3 (φfl = 0.63, 0.97). Energy levels of the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels estimated by cyclic voltammetry were to be –5.83, –6.0 eV and –2.85, –2.88 eV, respectively.

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