New breakthrough in solar cell research: materials of the future discovered!

New breakthrough in solar cell research: materials of the future discovered!

Scientists at Saarland University have developed an innovative method for analyzing rough silicon surfaces, which is particularly important for photovoltaic technology. This novel approach combines atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to precisely analyze surface roughness. The method is primarily used for black silicon, a nanostructured silicon surface that plays an important role in the efficiency of solar cells. The results of this research were published in the journal Small Methods uni-saarland.de reported.

The development of this method was driven by a team led by physics professor Karin Jacobs and colleagues from the German Aerospace Center (DLR). A central goal of the research is to correct the errors caused by surface roughness. XPS is known as an established method for determining the chemical composition of surfaces, but it has been shown to be prone to distortions on rough surfaces such as black silicon. Incorporating AFM measurements to accurately determine surface topography avoids traditional overestimation of oxide layer thickness.

The use of Minkowski tensors

A key to this improved analysis lies in the use of Minkowski tensors, which enable precise determination of the local slope of the surface. This creates the conditions for a more accurate determination of the oxide layer thickness on black silicon, which is only 50 to 80 percent thicker than the native oxide layer on conventional silicon wafers. Without the correction from the AFM data, the overestimation of the thickness could have been about 300 percent. Such advances in surface analysis technology are crucial for materials research and the development of new technologies in the fields of photovoltaics, optoelectronics and nanotechnology.

The research is funded by the German Research Foundation (DFG) as part of the priority program SPP 2265 and the Collaborative Research Center SFB 1027. This funding underlines the importance of the work for the future development of materials in the field of renewable energies, which is urgently needed to further increase the efficiency of solar cells.

A new approach to material development

In parallel to these developments, scientists from the Friedrich-Alexander University Erlangen-Nuremberg (FAU), the Helmholtz Institute Erlangen-Nuremberg and the Karlsruhe Institute of Technology (KIT) are working on a new workflow to search for high-performance materials for perovskite solar cells. This approach combines computational modeling and autonomous synthesis platforms with quantum theoretical calculations to predict appropriate material compounds and perform automated testing, reports fau.de.

The research, led by Prof. Christoph Brabec, has declared war on previous methods based on trial and error. Instead, a hybrid approach is taken that uses machine learning (ML) to predict molecular structures and properties. Around 100 molecules were used to train the models, which made it possible to identify the most powerful material candidates with efficiencies of up to 24 percent. These values ​​significantly exceed the previous reference value of 22 percent.

Overall, these research projects show how modern technologies and innovative approaches can work together to significantly increase the performance of solar cells. Using methods that enable both more precise measurements and targeted material developments, photovoltaics will be strengthened and further developed as a central technology for future energy production.