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.

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 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.

scholarly journals Photoconductivity of Low-Bandgap Polymer and Polymer: Fullerene Bulk Heterojunction Studied by Constant Photocurrent Method

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
V. V. Malov ◽  
A. R. Tameev ◽  
S. V. Novikov ◽  
M. V. Khenkin ◽  
A. G. Kazanskii ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Bulk Heterojunction ◽  
Inorganic Materials ◽  
Fullerene Derivative ◽  
Approximation Procedure ◽  
Photoelectric Properties ◽  
Highest Occupied Molecular Orbital ◽  
Donor Acceptor ◽  
Lowest Unoccupied Molecular Orbital ◽  
Doped Polymers

AbstractOptical and photoelectric properties of modern photosensitive polymers are of great interest due to their prospects for photovoltaic applications. In particular, an investigation of absorption and photoconductivity edge of these materials could provide valuable information. For these purpose we applied the constant photocurrent method which has proved its efficiency for inorganic materials. PCDTBT and PTB7 polymers were used as objects for the study as well as their blends with a fullerene derivative PC71BM. The measurements by constant photocurrent method (CPM) show that formation of bulk heterojunction (BHJ) in the blends increases photoconductivity and results in a redshift of the photocurrent edge in the doped polymers compared with that in the neat polymers. Obtained from CPM data, spectral dependences of absorption coefficient were approximated using Gaussian distribution of density-of-states within HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) bands. The approximation procedure allowed us to evaluate rather optical than electrical bandgaps for the studied materials. Moreover, spectra of polymer:PC71BM blends were fitted well by the sum of two Gaussian peaks which reveal both the transitions within the polymer and the transitions involving charge transfer states at the donor-acceptor interface in the BHJ.

scholarly journals Emphasizing the Operational Role of a Novel Graphene-Based Ink into High Performance Ternary Organic Solar Cells

2019 ◽  
Author(s):  
Minas M. Stylianakis ◽  
Dimitriοs M. Kosmidis ◽  
Katerina Anagnostou ◽  
Christos Polyzoidis ◽  
Miron Krassas ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Organic Solar Cells ◽  
High Performance ◽  
Energy Levels ◽  
Fullerene Derivative ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Synthetic Routes

A novel solution-processed graphene-based material was synthesized by treating graphene oxide (GO) with 2,5,7-trinitro-9-oxo-fluorenone-4-carboxylic acid (TNF-COOH) moieties, via simple synthetic routes. The yielded molecule N-[(carbamoyl-GO)ethyl]-N’-[(carbamoyl)-(2,5,7-trinitro-9-oxo-fluorene)] (GO-TNF) was thoroughly characterized and it was shown that it presents favorable highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels to function as a bridge component between the polymeric donor poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl}) (PTB7) and the fullerene derivative acceptor [6,6]-phenyl-C71-butyric-acid-methylester (PC71BM). In this context, a GO-TNF based ink was prepared and directly incorporated within the binary photoactive layer, in different volume ratios (1-3% ratio to the blend), for the effective realization of inverted ternary organic solar cells (OSCs) of the structure ITO/PFN/PTB7:GO-TNF:PC71BM/MoO3/Al. The addition of 2% v/v GO-TNF ink led to a champion power conversion efficiency (PCE) of 8.71% that was enhanced by ~13% as compared to the reference cell.

Cross-conjugation as a Motif for Organic Non-Linear Optical Molecules

2014 ◽  
Vol 1698 ◽  
Author(s):  
Meghana Rawal ◽  
Kerry Garrett ◽  
Andreas F. Tillack ◽  
Werner Kaminsky ◽  
Evgheni Jucov ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Dipole Moments ◽  
X Ray Diffraction ◽  
Conjugated Molecules ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Donor And Acceptor ◽  
Vis Spectroscopy ◽  
Lowest Unoccupied Molecular Orbital

ABSTRACTWe studied the effect of a cross-conjugated bridging group (χC) on charge-transfer in a push-pull chromophore system. The hyperpolarizability of such molecules was found to be comparable to that of a fully π-conjugated molecule (πC) with the same donor and acceptor. The cross-conjugated moiety was then applied as a pendant to a fully π-conjugated chromophore containing a tricyanopyrroline acceptor (TCP). The addition of a χC moiety did not alter the intrinsic hyperpolarizability and provides an avenue for extending and aiding πC systems. The molecules were examined by X-ray diffraction (XRD), hyper-Raleigh scattering (HRS) and UV-visible (UV-vis) spectroscopy. Experimental results were compared with the predictions of density functional theory (DFT). Cross-conjugated molecules have comparable β values, relative to πC molecules, due to reduced spatial overlap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Thus, the χC architecture could facilitate independent modification of donor and acceptor strengths while minimizing unfavorable effects on electronic transitions and dipole moments.

Electrochemistry, a Useful Tool in the Synthesis of Oligothiophenes

2021 ◽  
Vol 25 ◽  
Author(s):  
Fabiana Pandolfi ◽  
Martina Bortolami ◽  
Marta Feroci ◽  
Leonardo Mattiello ◽  
Vincenzo Scarano ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductors ◽  
Organic Solar Cells ◽  
Field Effect Transistors ◽  
Energy Levels ◽  
Organic Field Effect Transistors ◽  
Light Emitting ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Organic Photodetectors

: Thiophene derivatives, either "small molecules," oligomers or polymers, play a role of primary importance among organic semiconductors. Therefore they have numerous and different technological applications in the field of Organic Electronics. For this reason, thiophene-based materials are found in devices such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), organic solar cells (OSCs), organic photodetectors, and many others. Oligothiophenes and polythiophenes have in common excellent charge transport properties and synthetic procedures that are now well established. Furthermore, oligothiophenes do not possess the intrinsic disadvantages of polythiophenes, such as the lack of well-defined structures and the inevitable presence of impurities. Electrochemistry can give a significant contribution to the field of oligothiophenes not only by allowing the determination of the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO) energy levels by the means of cyclic voltammetry (CV), but also rendering oligothiophenes syntheses more expeditious in comparison with the classical organic ones. This review outlines the application of electrochemistry techniques to the synthesis of oligothiophene derivatives.

2,2′-[(Disulfanediyl)bis{5-[(1E)-(2-hydroxybenzylidene)amino]-1,3-thiazole-4,2-diyl}]diphenol: synthesis, crystal structure and calculation of molecular hyperpolarizability

2017 ◽  
Vol 73 (8) ◽  
pp. 609-612 ◽  
Author(s):  
Seyed Amir Zarei ◽  
Mohammad Piltan ◽  
Asmar Mashhun ◽  
Hadi Amiri Rudbari ◽  
Giuseppe Bruno
Keyword(s):  
Molecular Orbital ◽  
Condensation Reaction ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Highest Occupied Molecular Orbital ◽  
Molecular Hyperpolarizability ◽  
Lowest Unoccupied Molecular Orbital ◽  
Ir Spectroscopic ◽  
Base Compound

The title Schiff base compound {systematic name: 2-[5-[(E)-(2-hydroxybenzylidene)amino]-4-(2-{5-[(E)-(2-hydroxybenzylidene)amino]-2-(2-hydroxyphenyl)-1,3-thiazol-4-yl}disulfanyl)-1,3-thiazol-2-yl]phenol}, C32H22N4O4S4, incorporating a disulfanediyl (dithio) linkage, was obtained from the condensation reaction between two equivalents of salicylaldehyde and one equivalent of dithiooxamide in dimethylformamide, and was characterized by elemental analysis, IR spectroscopic analysis and single-crystal X-ray diffraction. A one-dimensional chain is formed along the b axis via double intermolecular C—H...S hydrogen bonds. The HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies and some related molecular parameters were calculated at the B3LYP/6-311G(d,p) level of theory. The molecular hyperpolarizability was also calculated.

scholarly journals An Effective D-π-A Type Donor Material Based on 4-Fluorobenzoylacetonitrile Core Unit for Bulk Heterojunction Organic Solar Cells

2021 ◽  
Vol 11 (2) ◽  
pp. 646
Author(s):  
Shabaz Alam ◽  
M. Shaheer Akhtar ◽  
Abdullah ◽  
Eun-Bi Kim ◽  
Hyung-Shik Shin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Organic Solar Cells ◽  
High Performance ◽  
Bulk Heterojunction ◽  
Energy Levels ◽  
Photovoltaic Properties ◽  
Donor Material ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

In order to develop new and effective donor materials, a planar donor-π-acceptor (D-π-A) type small organic molecule (SOM), 2-(4-fluorobenzoyl)-3-(5″-hexyl-[2,2′:5′,2″-terthiophen]-5-yl) acrylonitrile, named as H3T-4-FOP, was synthesized by the reaction of 4-fluorobenzoylacetonitrile (as acceptor unit) and hexyl terthiophene (as donor unit) derivatives. Promising optical, solubility, electronic and photovoltaic properties were observed for the H3T-4-FOP SOM. Significantly, the presence of 4-fluorobenzoylacetonitrile as an acceptor unit in H3T-4-FOP SOM tuned the optical band gap to ~2.01 eV and procured the reasonable energy levels as highest occupied molecular orbital (HOMO) of −5.27 eV and lowest unoccupied molecular orbital (LUMO) −3.26 eV. The synthesized H3T-4-FOP SOM was applied as a donor material to fabricate solution-processed bulk heterojunction organic solar cells (BHJ-OSCs) with an active layer of H3T-4-FOP: PC61BM (1:2, w/w) and was validated as having a good power conversion efficiency (PCE) of ~4.38%. Our studies clearly inspire for future designing of multifunctional groups containing the 4-fluorobenzoylacetonitrile based SOM for high performance BHJ-OSCs.

Impact of side-chain fluorination on photovoltaic properties: fine tuning of the microstructure and energy levels of 2D-conjugated copolymers

2017 ◽  
Vol 5 (32) ◽  
pp. 16702-16711 ◽  
Author(s):  
Jisoo Shin ◽  
Min Kim ◽  
Boseok Kang ◽  
Jaewon Lee ◽  
Heung Gyu Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Orbital ◽  
Polymer Solar Cells ◽  
Energy Levels ◽  
Fine Tuning ◽  
Side Chain ◽  
Photovoltaic Properties ◽  
Highly Efficient ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The control of the molecular energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is crucial to the design of highly efficient polymer solar cells (PSCs).

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