Synthesis and characterization of benzodithiophene-isoindigo polymers for solar cells
Artikel i vetenskaplig tidskrift, 2012

Three new alternating polymers with the electron-deficient isoindigo group as the acceptor unit and benzo[1,2-b:4,5-b'] dithiophene (BDT) or BDT flanked by thiophenes (or octylthiophenes) as the donor unit were designed and synthesized. All the polymers have good thermal stability, solubility and broad absorption spectra. Their photophysical, electrochemical and photovoltaic (PV) properties were investigated. To understand their different PV performance in the resulting polymer solar cells (PSCs), the morphology of their blends with fullerene derivatives was investigated by atomic force microscopy, and the molecular geometries as well as the molecular frontier orbitals were simulated by density functional theory calculations (Gaussian 09). The polymer PBDT-TIT, with BDT flanked by thiophenes as the donor unit and isoindigo as the acceptor unit, exhibits quite planar backbones and its blend with fullerene derivatives shows optimal morphology. As a result, the PSCs based on PBDT-TIT with a conventional device configuration of ITO/PEDOT: PSS/PBDT-TIT: PC(61)BM/LiF/Al showed a power conversion efficiency of 4.22%, with a short-circuit current density of 7.87 mA cm(-2), an open-circuit voltage of 0.79 V and a fill factor of 0.68 under the AM 1.5G illumination with an intensity of 100 mW cm(-2) from a solar simulator.

benzothiadiazole

copolymer

photovoltaic applications

conversion efficiency

donor

design

performance

density

conjugated polymers

polyfluorene

Författare

Z. F. Ma

Linköpings universitet

Ergang Wang

Chalmers, Kemi- och bioteknik, Polymerteknologi

Markus Jarvid

Chalmers, Kemi- och bioteknik, Polymerteknologi

Patrik Henriksson

Chalmers, Kemi- och bioteknik, Polymerteknologi

Olle Inganaes

Linköpings universitet

Fengling Zhang

Linköpings universitet

Mats Andersson

Chalmers, Kemi- och bioteknik, Polymerteknologi

Journal of Materials Chemistry

0959-9428 (ISSN) 1364-5501 (eISSN)

Vol. 22 5 2306-2314

Ämneskategorier

Kemiteknik

DOI

10.1039/c1jm14940g