Seminar: From model system to devices – Understanding solar cell materials with photoelectron spectroscopy

Solar cells have a great potential in replacing fossil fuels in electricity generation and the development of new types of solar cells is a large research field. In the last years, much research has focused on developing new solar cells made from organic or hybrid materials, which can be fabricated by cheap methods. This includes solar cells with a hybrid organic inorganic perovskite as the active layer in the solar cell, which have now reached power conversion efficiencies of more than 25%. In a typical solar cell, the perovskite layer is sandwiched between two selective contacts, one for holes and one for electrons.

The future success of these developments crucially depends on understanding the details of charge separation at the interfaces between the different layers in a solar cell as well as what parameters limit solar cell stability. X-ray based techniques such as photoelectron spectroscopy (PES) are powerful tools for obtaining electronic structure information of materials at an atomic level. In this talk, I will show how we obtain a better understanding of materials and interfaces for solar cells by investigating model systems as well as real solar cell devices with photoelectron spectroscopy.