Executive Summary : | Silicon PV technology has made great strides in reducing costs. However, the efficiency of the devices has mostly saturated at 25% because of a fundamental constraint – the Shockley Quiesser Limit (SQL). In this project, we aim to utilise the science of singlet exciton to break the SQL in silicon solar cells. Some organic molecules can convert one photon into two triplet excitons through singlet-fission. If both the resulting triplet excitons are harvested, the resulting quantum efficiency will be 200%! Unfortunately, practical demonstrations are few and far between because (a) conventional chromophores are not very efficient in converting singlet exciton to triplet exciton, and (b) conventional devices suffer significant interface recombination. In this project, we aim to solve both problems. We utilise the use of a new class of organic chromophores that have recently been demonstrated by the co-PI, which have much longer diffusion lengths. We shall also innovate in interface defect characterisation to reduce interface defects in our devices. |