Understanding exciton diffusion in organic solar cells

Abstract

Organic solar cells are promising candidates for future energy production. However, many challenges remain to optimise efficiency. One particular challenge lies in our understanding of the factors affecting exciton diffusion and the length scale of this process. This is particularly relevant to morphology optimisation for organic solar cells. A powerful tool to gain insight into this is femtosecond photophysical measurements. This thesis details work undertaken at the University of St Andrews between September 2009 and December 2010 towards a Masters of Philosophy. It includes an introduction to the field and a description of experimental methods used. Experimental chapters discuss measuring the optical constants of P3HT, a study of low concentration volume quenching, surface quenching measurements using titanium dioxide, surface quenching measurements using other quenchers and an investigation of the thickness dependence of the photoluminescence decay time in thin polymer films.