Arylene-ethynylene/arylene-vinylene copolymers: Synthesis and structure–property relationships

Effect of Varying Thiophene Units on Charge‐Transport and Photovoltaic Properties of Poly(phenylene ethynylene)‐alt‐poly(phenylene vinylene) Polymers

“…Particularly the 0-1 vibronic transition is rather pronounced due to the thiophene units, which enhances the planarization in the S 1 -state. [ 17,26,28 ] The optical band gaps ( E g opt ) of the polymers are rather similar 2.25 eV for TE-PV ab , 2.21 eV for BTE-PV ab , and 2.25 eV for EDOTE-PV ab and are slightly higher than the values derived electrochemically ( E g ec , Table 1 ). The polymers show tendencies of solvatochromism, a slight bathochromic shift in the absorption as well as in the photo-luminescence is observed when changing the solvent from chloroform to chlorobenzene.…”

“…[ 15 ] In contrast poly(phenylene ethynylene) (PPE) derivatives in which the vinyl double bonds of PPV backbone has been replaced by ethynyl triple bonds, possess relatively high reduction potentials (low-lying LUMO), [ 16 ] due to an enhanced electron affi nity induced by the electron-withdrawing character of the C C units. [ 17,18 ] Moreover PPEs possess a highly rigid conjugated structure leading to characteristics, which differ from the ones of PPV, e.g., polarization and molar extinction coeffi cients. They show especially high fl uorescence quantum yields in non-aggregated states (e.g., in dilute solutions), but very low fl uorescence quantum yields in aggregated states (e.g., in bulk fi lms) due to very strong interchain interactions creating multifarious radiationless deactivation pathways.…”

“…Moreover, the substitution of phenylene moieties by different aromatic structures creating poly(arylene ethynylene)-alt -poly(arylene vinylene) (PAE-PAV) systems further widens the options to tune and optimize the optoelectronic properties. [ 17 ] Polythiophene derivatives are also good candidates for organic photovoltaic applications. In particular poly(3-hexyl thiophene) (P3HT) has been extensively investigated as an effi cient donor material for photovoltaic devices exhibiting high short-circuit currents ( I SC ) of up to 10 mA cm −2 and power conversion effi ciencies of up to 5%.…”

Organometallic Approaches to Conjugated Polymers for Plastic Solar Cells: From Laboratory Synthesis to Industrial Production

“…It was demonstrated that the presence of ethynylene units in the polymeric backbone increases the oxidation potential of the polymer, which results in an increased open circuit voltage. [44] Moreover, the rigid rod structure typical of the PAEs might facilitate the intermolecular charge transport, [45] increasing short circuit current or the fill factor leading to enhanced performance of BHJ solar cells. The Pd-catalyzed Cassar-Heck-Sonogashira cross-coupling reaction represents, in most cases, the route of choice for incorporating conjugated structures containing triple bonds into the molecular backbone.…”

π‐Conjugated 2,2′:6′,2″‐Bis(terpyridines): Systematical Tuning of the Optical Properties by Variation of the Linkage between the Terpyridines and the π‐Conjugated System

“…The spectral behaviour, including fluorescence, closely resembles the findings with arylene-ethynylene/arylene-vinylene copolymers and their low-molecularmass model compounds, which have recently been reviewed. [48] …”