Photosensitizers in Solar Energy Conversion

Abstract

Today’s energy problems arise from the predicted exhaustion of fossil energy resources and the negative aspects of climate change. Additionally, the increasing energy needs and the improved environmental awareness of people all over the world necessitate the utilization of environmental friendly energy sources. The most abundant energy source is the sun. The solar energy is largely available, surpassing our annual energy demand by the factor of 10,000. Each second the sun produces enough energy to cover the energy demand for the whole humanity for 1,000,000 years. The dye-sensitized solar cell (DSC) concept is an interesting alternative to conventional silicon based solar cells due to its advantages of easy and fast fabrication, low production costs, short energy payback time and high photoelectric conversion efficiencies. In the following pages an overview shall be given of the operation principle of DSCs and the dyes used as sensitizers for solar energy conversion. The aim is to give an outline of the evolution of the DSC concept, the advantages and drawbacks of dye-sensitized systems and the different dyes (metal-organic and organic) applied in liquid and solid-state DSCs. Furthermore, the state of the art performance of the different types of dyes will be given.