Previous ERC funded research enabled us to develop a new methodology for modifying pi conjugated materials by chemically incorporating boron units. These materials possess many desirable properties, including small band gaps, excellent emission in the deep red and near-infra red region of the spectrum and good stability. This borylation process and the generated compounds were protected by the filing of a patent and one part of this proof of concept project was to synthesise more examples possessing these properties (and others) to facilitate a decision on their commercial potential and thus whether to pursue the patent process further (which costs significant amounts). Through this proof of concept grant additional materials were made and a partnership with a global electronics company strengthened to the stage where this company are funding the next steps of the patent process while they perform further evaluation testing in-house.
Another target of this proposal was to improve the first generation of our boron containing materials for application in Organic Light Emitting Diodes (OLEDs). OLEDs based on metal free emitters are desirable based on their relatively low cost, low toxicity, and ease of fabrication, but historically these were not competitive with the more expensive and toxic Ir / Pt based emitters when used in OLEDs. This is because metal free emitters have relatively low efficiency as light emission was inherently limited to using only 25% of excitons (in contrast Ir/Pt based emitters can harvest 100% of excitons). A recent approach has enabled metal free emitters in OLEDs to break this 25% barrier using the phenomena of thermally activated delayed fluorescence (TADF). However, highly emissive metal free TADF materials emitting in the deep red / Near infra red (NIR) region of the spectra remain challenging to access and there is still room for improvement on the current state of the art examples. This project successfully generated borylated pi conjugated materials that showed properties consistent with TADF and that were emissive in the far-red/NIR region of the spectrum. To date the OLEDs synthesised from these materials have not been sufficiently emissive to be commercially viable, however further work is ongoing to optimise these OLEDs. The proposal also developed an alternative use of these borylated materials, specifically as useful precursors to access “highly-twisted” aromatic materials rapidly in one-pot. “Highly-twisted” materials are the most common structural form in current TADF emitters, thus this new synthetic route will benefit those working in this important field and potentially lead to emissive materials for use in OLEDs. Overall this will help lower the cost of OLED products and accelerate the transition to lower energy consuming devices / lighting. Thus the societal benefits are not just based on the EU population getting access to cheaper consumer products, but are also linked to reductions in energy usage, with obvious implications for reducing CO2 output.
