Alternative energy sources such as solar cells demand is rapidly increasing due to the limited amount of fossil fuels that exist and the rising amount of CO2 in the environment. Organic solar cells have a low efficiency (~10%), but are cheap to produce. They consist of a blend of organic materials such as polythiothene (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM). They work by electrons in the P3HT HOMO level absorbing a photon, so that it jumps to the LUMO level, these electrons then move across to the PCBM LUMO level. This is known as charge transfer. In this experiment, we intend to probe the charge transfer in P3HT:PCBM using muons. The experiment will involve measuring the ALCs of P3HT and PCBM for light on and light off conditions and comparing the results.