They are 50,000 times thinner than a human hair, and barely a few atoms thick: two-dimensional materials are the thinnest substances that it is possible to manufacture today. They have completely new properties and are considered the next major step in modern semiconductor technology. In the future, they could be used instead of silicon in computer chips, light emitting diodes and solar cells. Until now, the development of new two-dimensional materials has been limited to structures with layers of rigid chemical bonds in two spatial directions – like a sheet of paper in a stack.
Now, for the first time, a research team from the universities of Marburg, Giessen and Paderborn, led by Dr Johanna Heine (inorganic chemistry, Philipps University of Marburg) has overcome this limitation using an innovative concept. The researchers developed an organic-inorganic hybrid crystal that consists of chains in one direction, but still forms two-dimensional layers despite this. This makes it possible to combine different material components, such as parts in a construction set, to create bespoke materials with innovative properties.
In this project, the research team combined the advantages of two-dimensional materials and hybrid perovskites – the eponymous mineral perovskite is well known for its optoelectronic properties and can be combined with other materials to improve these characteristics. “What’s special about it is that it offers completely new options for the targeted design of future functional materials,” says Dr Johanna Heine, chemist and junior research group leader at the University of Marburg , describing this area of research with great potential for application. “This physical effect – discovered for the first time here – could make it possible to adjust the color of future lighting and display technologies in a simple and targeted way,” says physicist Philip Klement, lead author and doctoral student in the group of research led by Professor Sangam Chatterjee at the Justus Liebig University of Giessen (JLU).
The work was carried out as part of an interdisciplinary collaboration: Dr Johanna Heine’s team at the University of Marburg first developed chemical synthesis and created the material as a single, loose crystal. Philip Klement and Professor Chatterjee’s team at JLU then used these crystals to produce individual atomically thin layers and studied them using optical laser spectroscopy. They found a broad spectral band (“white”) light emission, the color temperature of which can be adjusted by changing the thickness of the layer. In close collaboration with Professor Stefan Schumacher and his team of theoretical physicists from the University of Paderborn, the researchers carried out a microscopic study of the effect and were able to improve the properties of the material.
In this way, the researchers were able to cover the whole process, from the synthesis of the material and the understanding of its properties, to the modeling of the properties. Their results were published in the journal Advanced materials.
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Material provided by University of Paderborn. Note: Content can be changed for style and length.