We work on a variety of research topics in which we investigate the electronic structure and processes of polymeric and molecular organic semiconductors using optical spectroscopy and measurement on optoelectronic devices. Current projects include the topics listed below.

Phosphorescent polymer light-emitting diodes

Efficient organic light-emitting diodes (OLEDs) are typically made by combining different charge transporting materials and phosphorescent materials. By time-resolved photoluminescence studies, Monte-Carlo simulations and OLED measurements, we study the dynamics of excited states in such systems with a view to understanding and improving the energy and charge transfer processes in such OLEDs.

Excited state dynamics in organic solar cells

Efficient organic solar cells are often based on a multicomponent structure. At present, very little is known how the photo-excited coulomb bound electron-hole pair separates at the interface between dissimilar organic semiconductor materials. In this study, we use time-resolved spectroscopy to follow the dynamics of excited state formation and dissociation. This is combined with measurements on solar cell structures. An understanding of these issues is essential for the design of efficient solar cells.

The effect of self-assembly on opto-electronic processes

Organic semiconductors can be designed to self-assemble into a range of supramolecular structures.In this research area, we study how the optical and electronic properties of such assemblies depend on the nature of the inter-molecular interactions, and how this affects the properties of OLEDs, solar cells and transistors.