Self-assembling conjugated macromolecules for organic field effect transistors and solar cells
Lead Research Organisation:
Imperial College London
Department Name: Physics
Abstract
The design and construction of an ideal material for organic semiconductor devices requires the careful consideration of a range of physical properties. In some cases, what would represent good materials characteristics for one type of device may be highly detrimental to the efficiency of another. Intermolecular pi-pi interactions symbolise one good example: in organic light emitting devices, photoluminescence is quenched by these attractions and the device efficiency is reduced dramatically; in organic field effect transistors (OFETs), it is desirable to promote pi-pi interactions throughout the bulk, so that charge mobility can be maximised. In this proposal, we aim to prepare materials for organic photovoltaic (OPV) devices and OFETs. The novelty in this work originates from very recent results, in which we demonstrate that highly soluble materials with conformational freedom in solution are able to self-assemble in the solid state to give highly planar and conjugated structures. Such levels of planarity, which maximise the possibility of pi-pi interactions, have only been achieved previously with ladder or ribbon type structures which possess inherent solubility problems. In our systems, long range planarity can be achieved through the use of weak, non-covalent interactions; to date, this approach has not been given significant consideration and is therefore waiting to be exploited.
Publications
Hamilton R
(2009)
High-Performance Polymer-Small Molecule Blend Organic Transistors
in Advanced Materials
Smith J
(2010)
The Influence of Film Morphology in High-Mobility Small-Molecule:Polymer Blend Organic Transistors
in Advanced Functional Materials
Smith J
(2008)
High-performance organic integrated circuits based on solution processable polymer-small molecule blends
in Applied Physics Letters
Smith J
(2010)
Air-stable solution-processed hybrid transistors with hole and electron mobilities exceeding 2 cm2 V-1 s-1.
in Advanced materials (Deerfield Beach, Fla.)
Smith J
(2011)
Percolation behaviour in high mobility p-channel polymer/small-molecule blend organic field-effect transistors
in Organic Electronics
Smith J
(2010)
Solution-processed organic transistors based on semiconducting blends
in Journal of Materials Chemistry