Luminescent Conjugated Polymers for Energy Materials

The development of new materials for energy applications is of utmost importance both nationally and internationally in order to establish energy generation, storage and usage in a secure and environmentally friendly manner.

Conjugated polymers have been successfully applied to virtually all aspects of energy materials with promising results but so far their efficiency and performance has generally failed to match those of competing technologies. The origin of their poorer performance can generally be traced back to their low luminescence efficiencies which results in large amounts of energy being lost as waste heat. This is particularly evident in applications where there is a conversion from light to electricity (e.g. solar cells), or the reverse process (e.g. light emitting devices).

This proposal will deliver two new materials platforms which will drastically enhance the luminescence efficiency of conjugated polymers, both in neat films and in blends substantially increasing their performance and allowing for them to be used in the next generation of energy materials applications.
The two main strategies that will be employed to achieve this will be to i) encapsulate the conjugated polymer backbone such that low energy non-emissive aggregate species cannot form and ii) the creation of polymers with narrow singlet-triplet energy gaps which can convert 'dark' triplets into 'bright' singlets through reverse intersystem crossing. Therefore, through the combination of precise interchain and energetic manipulation we will eliminate non-radiative loss mechanisms in conjugated polymers. These materials will then be implemented into a wide variety of energy applications such as solar cells, light emitting diodes, light emitting transistors and sensors for battery applications. Additionally, these materials will allow for advancements in virtually all conjugated polymer applications such as fluorescence imaging, photodynamic therapy, photocatalysis and bioelectronics.

These two new materials platforms will thus deliver fundamental scientific advances in the field of conjugated polymer design which will result in a new generation of high performance, low loss energy applications with ramifications throughout all fields where there is light-matter interaction.

The scientific advancements within this proposal would have significant impact on all academic and industrial environments that involve light-matter interactions, predominantly in the field of energy research but also in areas as diverse as photonics and biomedical research.

The immediate beneficiaries of the proposed work will be the national and international academic and industrial communities involved in plastic electronics research, which itself spans many disciplines including chemistry, physics, materials science. It will provide researchers new chemical strategies to overcome the current limitations of conjugated materials and a pathway to the fabrication of higher efficiency devices (such solar cells, light emitting diodes, light emitting transistors and lasers), enabling the research community to become competitive with the current market leaders. The output from this proposal would therefore impact the numerous companies directly involved in the commercialisation of conjugated materials and their applications in devices such as Cambridge Display Technology, Eight19, Plastic Logicin the UK and Merck, BASF, Solvay, Next Energy Technologies, Heliatek, Solarmer, SONY and LG internationally.

This work also significantly impacts academic and industrial research outside of the immediate field of plastic electronics. They advancements we will deliver are to develop polymers which are highly emissive, predominantly in the red/near-IR region of the electromagnetic spectrum. Furthermore, one of the strategies we will use to achieve this will be through the generation of long lived excited states. These advances are highly relevant to sensing and healthcare technologies. Our proposed materials are therefore of direct significance to academic and industrial research in biomedical imaging, photodynamic therapy, sensors, spintronics and photonics in general.

The organic electronics industry set to be worth $75.82 Billion by 2020 indicating that national scientific and industrial leadership in this area would have a significant positive effect on both the knowledge and wealth economy. The resulting highly trained staff and students would be of direct benefit to the UK economy. Furthermore, the general public has an appetite for green technology which this proposal would deliver, enhancing public engagement. Finally, the UK government has committed to reducing its carbon footprint and developing green energy sources and good energy security. The development of efficient, low cost energy materials within this proposal directly addresses this urgent need, giving strong socio-economic benefits to the entire nation.