The perfect geometry for solar cells

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Prof. Dr. Julien Bachmann (Image: FAU/Erich Malter)

FAU researcher Prof. Dr. Julien Bachmann receives ERC grant of 1.9 million euros

FAU has counted another success in the tough competition for European research funding, as Prof. Dr. Julien Bachmann has been awarded the European Research Council’s (ERC) prestigious 1.9-million-euro ERC Consolidator Grant for his latest research project. The chemist’s goal is to develop efficient solar cells made from low-cost, sustainable nanomaterials.

Unlike first-generation solar cells which are made of silicon, third-generation solar cells can be made of low-cost and sustainable materials thanks to nanostructuring. This is a huge advantage for the expansion of renewable energies. However, the modern technology is less efficient than the standard silicon cells. A possible reason for this may be the disorderly geometry of the nanostructures used, which is in stark contrast to the highly ordered nanostructures of the surfaces where energy transformations take place in nature. For example, in photosynthesis the energy of sunlight is stored in chemical form as fuel thanks to the perfect arrangement of the structures on the nanoscale. This is the starting point for Professor Bachmann’s project. He wants to design the nanoscale geometry of the material interfaces in a targeted way in order to systematically study their properties.

Over the next five years, Bachmann and his working group will concentrate on cylindrical nanostructures. By changing the geometry of the materials, they aim to find out which physical and chemical processes affect the efficiency of solar cells, and in what way. Finding the perfect area sizes is key here, as when it comes to efficiency there is an intrinsic contradiction in the design of solar cells. The larger the area between the two materials – the two semiconductors – the more light is absorbed and the more electricity is generated. However, the larger this area is made through longer nanostructures, the further the electrons have to travel in order to generate electricity. As a consequence, more energy is lost and less electricity is generated. Taking this contradiction into account, Bachmann’s goal is to find the perfect geometry required to achieve the best possible properties.

Prof. Julien Bachmann has been professor of inorganic chemistry at FAU since 2012. He has extensive knowledge of two areas, synthetic chemistry and solid-state physics. After studying molecular chemistry at the University of Lausanne in Switzerland, Bachmann completed a PhD in inorganic chemistry at the Massachusetts Institute of Technology (MIT) in the USA. Starting in 2006, he received an Alexander von Humboldt research fellowship and worked as a researcher at the Max Planck Institute of Microstructure Physics in Halle and at the University of Hamburg. In 2009, he was appointed as a junior professor at the University of Hamburg’s physics department. Bachmann was awarded an EAM Starting Grant in 2013 as part of the programme run by FAU’s Cluster of Excellence ‘Engineering of Advanced Materials’ (EAM) to support its best young researchers. This was clearly a success, as Prof. Bachmann is now part of the exclusive group of researchers who have been awarded an ERC Consolidator Grant. The ERC awards these grants for excellent ground-breaking research projects.

Further information:

Prof. Dr. Julien Bachmann

Phone: +49 9131 8527396