In:
Advanced Functional Materials, Wiley, Vol. 25, No. 1 ( 2015-01), p. 150-157
Abstract:
Current organic semiconductors for organic photovoltaics (OPV) have relative dielectric constants (relative permittivities, ε r ) in the range of 2–4. As a consequence, Coulombically bound electron‐hole pairs (excitons) are produced upon absorption of light, giving rise to limited power conversion efficiencies. We introduce a strategy to enhance ε r of well‐known donors and acceptors without breaking conjugation, degrading charge carrier mobility or altering the transport gap. The ability of ethylene glycol (EG) repeating units to rapidly reorient their dipoles with the charge redistributions in the environment was proven via density functional theory (DFT) calculations. Fullerene derivatives functionalized with triethylene glycol side chains were studied for the enhancement of ε r together with poly( p ‐phenylene vinylene) and diketopyrrolopyrrole based polymers functionalized with similar side chains. The polymers showed a doubling of ε r with respect to their reference polymers in identical backbone. Fullerene derivatives presented enhancements up to 6 compared with phenyl‐C 61 ‐butyric acid methyl ester (PCBM) as the reference. Importantly, the applied modifications did not affect the mobility of electrons and holes and provided excellent solubility in common organic solvents.
Type of Medium:
Online Resource
ISSN:
1616-301X
,
1616-3028
DOI:
10.1002/adfm.201402244
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2029061-5
detail.hit.zdb_id:
2039420-2
SSG:
11
