Optoelectronic Nanostructures via Polythiophene Block Copolymer Self-Assembly

Lead Research Organisation: University of Cambridge
Department Name: Physics

Abstract

Conjugated organic molecules and polymers possess the electronic properties of inorganic semiconductors and metals, while being of lower cost, lighter weight and more amenable to device manufacture. Furthermore, these properties can be readily controlled by manipulation of the molecular or macromolecular structure, which offers a distinct advantage over many comparable inorganic materials. As a result, organic replicas have now found applications as wires, light-emitting diodes, sensors, field-effect transistors, photovoltaic devices and lasers.The optimisation of many such devices, however, relies on either balancing charge carrier transport or manipulating the diffusion of excitons, both of which require control over the supramolecular structure. Unfortunately, the patterning of conjugated organic units into nanoscale objects of predetermined size and shape remains a fundamental challenge. This problem is further amplified by the need for more complex architectures, such as junctions or compartmentalised structures and composites, for the extensive realisation of nanoscale organic replicas of inorganic microelectronic components.

In this collaborative proposal we target proof of concept studies that will permit the development of a new platform for the creation of functional 1-D semiconducting nanostructures based on block copolymers with crystalline, pi-conjugated polythiophene segments. This offers the simplicity of solution phase self-assembly but affords potential control over the dimensions of the structure. Furthermore, this new method also offers exciting possibilities for accessing both compartmentalised and hybrid structures, which should function as key components in a variety of nanoscale devices.

Publications

10 25 50
 
Description Novel micellar structures synthesised at the University of Bristol have been studied in Cambridge. These contain well-organised short semiconductor polymer chains that form structures of several hundred nanometers. Our measurements of time-resolved luminescence reveal that photoexcitations are able to diffuse up to 200 nm - an exceptionally large range for any molecular semiconductor. These results were published in Science (2018).
Exploitation Route These structures are potentially useful as light-harvesting elements in novel photodetectors
Sectors Electronics,Energy

URL https://www.phy.cam.ac.uk/news/plastic-crystals-hold-key-to-record-breaking-energy-transport
 
Description This project resulted in a significant paper (Science, 2018) in which we report nano-platelet semiconductor structures that show important optoelectronic properties. Specifically, the energy from absorbed light (in the form of 'molecular excitons) can move a significant distance within these structures, and this is very attractive for light-harvesting applications in photodetectors or solar cells.
First Year Of Impact 2018
Sector Electronics,Energy
Impact Types Economic