Active Triplet-Mediator Matrices for Efficient Solid-State Triplet-Triplet Annihilation Photon Upconversion Devices

Solar irradiation offers the possibility of clean and renewable energy worldwide.

One major challenge for solar energy conversion is the uncollected and wasted energy from the solar spectrum, photons with energy lower than the bandgap of photovoltaic materials are lost.

A mere 1% utilization of low bandgap photons in today’s solar energy installations would result in an additional 3 GW produced capacity, equivalent to 5 nuclear power plants.

Triplet-triplet annihilation upconversion (TTA-UC) provides the possibility to convert two photons of low energy to one of high energy even at low irradiation intensity.

This allows the two unused photons otherwise penetrating the photovoltaic to be transformed into one useable photon The development of efficient TTA-UC systems, compatible to solar energy harvesting devices is therefore of pivotal importance. This project aims at fabricating a material that enables efficient solar energy harvesting at low photon energies.

Specifically, we will do this through solid state triplet-triplet annihilation upconversion. I will employ novel organometallic sensitizers that allow for low energy harvesting.

These sensitizers will be incorporated into an active host matrix that replaces molecular diffusion, with triplet exciton diffusion.

This is a novel realisation of energy transfer in the solid state and will circumvent current limitations in solid state upconversion. This will yield an efficient TTA-UC solid state material that can be applied to devices.

By fulfilling these tasks, this research project will ultimately contribute to a new strategy for enhancement of solar energy conversion.