Synthesis and Characterization of a 2,3-Dialkoxynaphthalene-Based Conjugated Copolymer via Direct Arylation Polymerization (DAP) for Organic Electronics

Abstract

Poly[(5,5’-(2,3-bis(2-ethylhexyloxy)naphthalene-1,4-diyl)bis(thiophene-2,2′-diyl))-alt-(2,1,3-benzothiadiazole-4,7-diyl)] (PEHONDTBT) was synthesized for the first time and through direct arylation polymerization (DAP) for use as p-donor material in organic solar cells. Optimized reaction protocol leads to a donor-acceptor conjugated polymer in good yield, with less structural defects than its analog obtained from Suzuki polycondensation, and with similar or even higher molecular weight than other previously reported polymers based on the 2,3-dialkoxynaphthalene monomer. The batch-to-batch repeatability of the optimized DAP conditions for the synthesis of PEHONDTBT was proved, showing the robustness of the synthetic strategy. The structure of PEHONDTBT was corroborated by NMR, exhibiting good solubility in common organic solvents, good film-forming ability, and thermal stability. PEHONDTBT film presented an absorption band centered at 498 nm, a band gap of 2.15 eV, and HOMO and LUMO energy levels of −5.31 eV and −3.17 eV, respectively. Theoretical calculations were performed to understand the regioselectivity in the synthesis of PEHONDTBT and to rationalize its optoelectronic properties. Bilayer heterojunction organic photovoltaic devices with PEHONDTBT as the donor layer were fabricated to test their photovoltaic performance, affording low power-conversion efficiency in the preliminary studies.

New Hybrid Copper Nanoparticles/Conjugated Polyelectrolyte Composite with Antibacterial Activity

“…A signal at 450 nm is observed in CPE spectra, while in CuNP/CPE, the spectra are centered at 435 nm. This band originates from the intramolecular charge transfer (ICT) process between the electron-donor (fluorene) and electron-acceptor (naphthotriazole) units along with the CPE structure [ 60 , 61 , 62 ]. The spectrum of an oxidized CuNP/CPE suspension was also recorded, showing the two absorption bands expected but shifted in relation to the maximum peaks of the stabilized suspension.…”

New Benzotriazole and Benzodithiophene-Based Conjugated Terpolymer Bearing a Fluorescein Derivative as Side-Group: In-Ternal Förster Resonance Energy Transfer to Improve Organic Solar Cells

“…π-Conjugated polymers (CPs) have been widely studied during the last decades due to the unique combination of optical and electronic properties, such as sunlight harvesting capability and charge carrier mobility, with those inherent to synthetic polymers, such as structural and functional versatility, solution processability, flexibility, and light weight [ 1 , 2 , 3 ]. This set of properties makes them suitable for many commercial applications, such as organic solar cells (OSCs), organic light-emitting diodes (OLEDs), organic field-effect transistors (OFET), and sensors, among others [ 4 , 5 , 6 , 7 , 8 ]. Regarding its photovoltaic applications, the CPs must have a relatively low bandgap, suitable HOMO/LUMO energy levels, broad absorption in the visible region, solubility in common organic solvents, and proper charge transport to be used as active layers in high-performance OSCs [ 9 , 10 ].…”

Polyferrocenylsilane Semicrystalline Polymer Additive for Solution-Processed p-Channel Organic Thin Film Transistors

“…Polymeric materials as additives have rapidly attracted considerable attention for application in organic electronics [ 1 , 2 , 3 , 4 , 5 ]. When they are blended with organic semiconductors, those polymers demonstrate various merits in controlling the crystal growth, enhancing the semiconductor morphology, and improving the electrical performance of organic thin film transistors (OTFTs) [ 6 , 7 ].…”