Organometal halides for photovoltaic applications

Reducing carbon dioxide emissions and our reliance on fossil fuels are some of the biggest challenges facing society in the 21st century. As a result, we are continuously looking for new and improved materials for energy storage and energy conversion. A range of different technologies will be used to meet future energy demands, such as batteries, fuel cells and photovoltaics. Since first being used in a photovoltaic device in 2009, the efficiencies of CH3NH3PbI3 based solar cells have increased dramatically from 3.8% to 25.5%. This has been accompanied by optimisation of chemical composition, film processing and device architecture. The high efficiencies are already comparable with more established solar cell technologies and the low temperature synthesis and processing of these materials has resulted in intense worldwide interest in these materials. These organometal halides exhibit a huge degree of structural and compositional flexibility, and depending on the cations and anions chosen, new materials can be formed, differing in the connectivity of the metal halide octahedra and this can influence the properties displayed. Two of the biggest challenges currently faced by CH3NH3PbI3 based photovoltaics are their long term stability and reducing the lead content. This project will look at the synthesis, characterisation, properties and stability of organometal halides. In particular, we will focus on the discovery of lead free materials and the stability of the materials upon exposure to humidity and light.