Novel Polymers of Intrinsic Microporosity for Use as Photonic Materials

Lead Research Organisation: University of Glasgow
Department Name: School of Chemistry

Abstract

Printed electronics is a rapidly growing field, generating a remarkable array of new technologies for lighting, displays, power and sensors. Curved and bendable OLED screens are already in mass production in smart phones and wearables; lightweight plastic solar cells will soon adorn buildings; smart labels and packaging will include sensors that update integrated displays.

To make these new technologies very cheaply and in large area it is necessary to print the semiconducting materials from solution (from specialised electronic inks). A very important class of printable semiconductors are conjugated polymers which can strongly absorb light for solar cells, efficiently emit light as lasers, lighting and displays, perform simple logic operations, and respond as sensors for chemicals. To make these long chain molecules processable from solution, however, they require long, oily side groups which constitute around half the mass of the material. This currently necessitates a compromise between the processability of the polymers and their electronic, optical and thermal properties.

This proposal will develop a new approach to printable polymers which avoid such a compromise in materials properties, then aims to demonstrate it in example applications of sensors, solar cells and lasers. These will be based on polymers of intrinsic microporosity (PIMs), a class of materials currently used for gas separation and capture. PIMs are highly soluble, rigid and contorted long chain molecules, which have been designed so that the chains in a thin film pack inefficiently to create a network of interconnected voids, giving a microporous structure.

We will design and synthesise new types of PIMs with repeating units that provide tailored optical and electronic properties suitable for the applications of printed electronics. We shall measure their physical, optical and electronic properties to understand structure-function relationships. We will then develop three carefully chosen exemplar device studies (in chemical sensors, lasers and solar cells) to test the utility of their distinctive properties. By omitting the oily side groups from the polymer, we will confer high temperature stability to the materials, which will allow devices to operate more reliably. Tailored molecular docking sites will enable chemical sensing interactions with the vapours of concealed explosives or the products of food decay. Amorphous thin films will be imprinted and doped to form miniature visible plastic lasers. Enhanced absorption, and control of the electronic interfaces between different organic semiconductors shall present new opportunities for large-area printed solar cells.

As the scientific results from our project advance, we will actively seek the best opportunities for generating impact from the new materials. We shall work with project partners DSTL (the UK Defence Science and Technology Laboratory) and the Swedish EOD and Demining Centre (SWEDEC) to test new sensors made from these materials for detecting trace levels of explosives, and assess them in field conditions. We plan to work with the Knowledge Transfer Network and the Scottish Innovation Centres to explore opportunities for the other device applications, and engage with polymer manufacturers to identify pathways for scale-up and future use.

Publications

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Description We have synthesised a number of new polymers that may be candidates as polymers of intrinsic microporosity. We are currently evaluating their properties at partner institutions (University of Edinburgh and St-Andrews).
We are also investigating their sensor, photovoltaic properties and organic laser applications at the University of Edinburgh.
Exploitation Route If the materials prove to be PIMs and have application as sensors, solar cells or organic lasers they will be of interest to a range of scientists in the optoelectronics area.
Sectors Chemicals

Electronics

Energy