Temperature-Tuning of Optical Properties and Molecular Aggregation in AnE-PVstat Copolymer Solution

Abstract

The correlation between the optical and morphological properties of an anthracene-containing poly­(phenylene ethynylene)-alt-(phenylenevinylene) statistical copolymer (AnE-PVstat) in solution has been investigated. As a function of temperature, the molecular aggregation in chloroform/chlorobenzene (CF:CB) solution was examined by means of absorbance and photoluminescence measurements. The study of the evolution of the 0–0 to the 0–1 photoluminescence (PL) ratio with temperature in the framework of the HJ-aggregate model unveiled the presence of both H- and J-like behaviors at room temperature. Upon increasing temperature, the interchain intermolecular coupling decreases, leading to a dissociation of H-aggregates. Hence, molecular torsions are facilitated, polymer planarity is reduced, and the intrachain electronic coupling decreases.

A Thiazole–Naphthalene Diimide Based n-Channel Donor–Acceptor Conjugated Polymer

“…For PNDI2Tz p -xylene solutions, the polymer absorption maxima remained at ∼540 nm (2.3 eV) even when the temperature was increased to 100 °C (Figure S7), suggesting that the copolymer does not tend to self-assemble into aggregated structures at room temperature. The small 5 nm blue-shift in λ max and decreasing intensity over the 25–100 °C temperature range can be attributed to decreases in conjugation length with increasing molecular disorder at higher temperatures. − …”

Aging of quinoxaline-based polymer solar cells under UV-free white light

“…In fact, sidechain engineering has played an essential role in optimizing the specic properties of conjugated polymers, such as molecular weight, absorption, emission, inter-and intramolecular interactions, charge transport, and active layer morphology in blends. [56][57][58] Here, we report on the performance and stability of devices consisting of quinoxaline-based donor polymers employed in solar cells in combination with the acceptors PC 70 BM and ITIC. To assess the degradation of the solar cells, the devices were exposed to laboratory weathering tests using UV-free white light emitting diodes (LED) and controlled environmental conditions in line with the ISOS protocol L1.…”

“…In fact, side-chain engineering has played an essential role in optimizing the specific properties of conjugated polymers, such as molecular weight, absorption, emission, inter- and intramolecular interactions, charge transport, and active layer morphology in blends. 56–58…”

Influence of thermal annealing on microstructure, energetic landscape and device performance of P3HT:PCBM-based organic solar cells

“…Several techniques have been used to promote nanoscale phase separation, polymer crystallization, and chain alignment in BHJ solar cells and FETs [37][38][39][40]. Previous work suggests that polymer chain alignment and crystallization can readily be controlled by spin coating conditions, solution concentration and composition, film drying conditions, surface modification, and selectivity of the transport layer [24,[41][42][43][44][45]. Post-processing thermal annealing is one of the most commonly used methods to alter the crystallization of semi-crystalline organic thin films [46][47][48][49].…”