High entropy organic semiconductor blends for new optoelectronic and photonically active materials

Limiting global warming to 1.5 C requires net zero CO2 emissions by 2050 and necessitates renewable electricity reaching 63-81% of total energy generation. Photovoltaic technologies are forecast to be at the centre of future renewable electricity generation. Solar energy conversion materials could enhance silicon photovoltaic efficiencies up to 30% by either converting each high energy photon into two lower photons (down-conversion) or through converting two low energy photons into a single higher energy photon (up-conversion) with minimal energy losses.

Whilst down-conversion and up-conversion systems have high efficiencies in solution, translation to solid state films results in significant efficiency losses due to sub-optimal morphologies, which prevents the deployment of these materials with photovoltaics.

This project will develop new ways to tune molecular packing in small molecule organic semiconductors utilising the approach of high entropy materials were five different organic semiconductors will be blended together. Utilising a well-defined suite of organic semiconductors possessing different solubilising groups and different conjugated cores will enable design rules for the molecular packing and morphology to be established for these.

Further, the potential for coupling organic high entropy materials with quantum dots will be explored as a highly promising route for overcoming to longstanding problem of aggregation in hybrid organic/quantum dot composites.

To explore the complex formulation space of systems containing many components will be accelerated through utilising a robotic platform for automated high-throughput material preparation.

The candidate will explore the formulation, structure, and function of the films, including their crystallisation and self-assembly behaviour. This project will develop valuable industrially-relevant skills in solution processing of thin films, spin coating, blade coating, organic electronics, and device fabrication and in detailed quantification of morphology through employing techniques including X-ray scattering, atomic force microscopy, electron microscopy and optical microscopy.