Synthesis of Semiconducting Polymers for use in Organic Electronics
Author(s)
Donaghey, Jenny E.
Type
Thesis
Abstract
A series of novel semiconducting co-polymers based on known, fused aromatic monomers
(dibenzosilole, dithienosilole and dithienopyrrole) were synthesized for use in organic field
effect transistor (OFET) devices. The fused monomers were copolymerized with triarylamine
and thienothiophene units to give a series of six donor polymers. Their electronic energy
levels were probed by UV-Vis and photoelectron spectroscopy, and predictions regarding
their performance were drawn from this information. Two polymers were tested in OFETs
and conclusions were made concerning the relationship between structure and performance.
Four donor-acceptor type polymers were synthesized using dithienopyrrole as the electron
rich unit. This monomer was copolymerized with benzothiadiazole, difluorobenzothiadiazole,
thienopyrrolodione and 1,1’-bithienopyrrolodione. These low band gap polymers were tested
as the donor polymer in polymer:fullerene BHJ devices.
A novel monomer with long branched alkyl substituents, based on the extended fused-ring
system indacenodithiophene (IDT), was synthesized. The nitrogen analogue of this monomer
(NIDT) was of interest as its performance could be compared to the carbon and silicon
versions of IDT. A route to NIDT was devised and then it was polymerized with four electron
poor monomers. The energy levels were estimated by UV-Vis and photoelectron
spectroscopy, followed by testing of the materials in OFET and OPV devices. Those with the
lowest lying HOMO levels performed best in OPVs.
Another series of NIDT containing polymers were synthesized, designed specifically for use
in OFET devices. The aim was to produce polymers with highly planar backbones which
would form ordered domains and enhance hole transport. An NIDT monomer was
synthesized with linear hexadecyl substituents in order to improve π-stacking. The linear
NIDT monomer was then copolymerized with thiophene, thienothiophene,
thienopyrrolodione and diketopyrrolopyrrole. It was found that the diketopyrrolopyrrole
containing polymer, performed best in OFETs and the molecular weight played a large role in
how a polymer performed.
(dibenzosilole, dithienosilole and dithienopyrrole) were synthesized for use in organic field
effect transistor (OFET) devices. The fused monomers were copolymerized with triarylamine
and thienothiophene units to give a series of six donor polymers. Their electronic energy
levels were probed by UV-Vis and photoelectron spectroscopy, and predictions regarding
their performance were drawn from this information. Two polymers were tested in OFETs
and conclusions were made concerning the relationship between structure and performance.
Four donor-acceptor type polymers were synthesized using dithienopyrrole as the electron
rich unit. This monomer was copolymerized with benzothiadiazole, difluorobenzothiadiazole,
thienopyrrolodione and 1,1’-bithienopyrrolodione. These low band gap polymers were tested
as the donor polymer in polymer:fullerene BHJ devices.
A novel monomer with long branched alkyl substituents, based on the extended fused-ring
system indacenodithiophene (IDT), was synthesized. The nitrogen analogue of this monomer
(NIDT) was of interest as its performance could be compared to the carbon and silicon
versions of IDT. A route to NIDT was devised and then it was polymerized with four electron
poor monomers. The energy levels were estimated by UV-Vis and photoelectron
spectroscopy, followed by testing of the materials in OFET and OPV devices. Those with the
lowest lying HOMO levels performed best in OPVs.
Another series of NIDT containing polymers were synthesized, designed specifically for use
in OFET devices. The aim was to produce polymers with highly planar backbones which
would form ordered domains and enhance hole transport. An NIDT monomer was
synthesized with linear hexadecyl substituents in order to improve π-stacking. The linear
NIDT monomer was then copolymerized with thiophene, thienothiophene,
thienopyrrolodione and diketopyrrolopyrrole. It was found that the diketopyrrolopyrrole
containing polymer, performed best in OFETs and the molecular weight played a large role in
how a polymer performed.
Date Issued
2012-03
Date Awarded
2012-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Williams, Charlotte
McCulloch, Iain
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)