The synthesis and properties of two semiconducting donor-acceptor (D-A)
block copolymers and their application in nanostructured bulk heterojunction
solar cells are reported. The donor segments were obtained via nitroxide
mediated polymerization of either bis(4-methoxyphenyl)-4'-vinylphenylamine
or
N,N'-bis(4-methoxyphenyl)-N-phenyl-N'-4-vinylphenyl-[1,1'biphenyl]-4,4'-diamine.
Narrow-distributed macroinitiators,
poly{bis(4-methoxyphenyl)-4'-vinylphenylamine} (PvDMTPA) and
poly{N,N'-bis(4-methoxyphenyl)-N-phenyl-N'-4-vinylphenyl-[1,1'biphenyl]-4,4'-diamine}
(PvDMTPD) were used to polymerize the acceptor monomer perylene diimide
acrylate (PerAcr) to yield block copolymers with well-defined molecular
weights. Different diblock copolymers, PvDMTPA-block-PPerAcr and
PvDMTPD-block-PPerAcr, with high perylene diimide weight fractions were prepared.
The block copolymers exhibited efficient fluorescence quenching.
Transmission electron microscopy revealed wire-like and worm-like
nanostructures throughout bulk samples. Thin film photovoltaic devices
showed short circuit currents $J_{\it SC}$ of up to 1.21 mA/cm2 and power conversion efficiencies η
of 0.32% under AM 1.5 illumination conditions.