Researchers transform algae into unique functional perovskites with desired properties

The team, led by scientists from the B CUBE - Centre for Molecular Bioengineering at TU Dresden, converted the mineral shells of the algae into lead halide perovskites with specific physical properties. The new perovskites have unique nanoarchitectures that cannot be achieved by conventional synthesis. Single-cell organisms can thus be used for the mass production of perovskites with desired structural and electro-optical properties. The results were published in the scientific journal Advanced Science.

Perovskites are materials that are becoming increasingly popular for a variety of applications due to their remarkable electrical, optical and photonic properties. Perovskites have the potential to revolutionise the fields of solar energy, sensing and detection, photocatalysis, lasers and others.

The properties of perovskites can be customised for specific applications by changing their chemical composition and internal architecture, including the distribution and orientation of the crystal structure. At present, the possibilities for influencing these properties are severely limited by the manufacturing methods. A research team at TU Dresden has succeeded in producing perovskites with unique nanoarchitectures and crystal properties from algae, utilising the many years of evolution of these unicellular organisms to their advantage.

Taking advantage of evolution
„Over hundreds of millions of years, unicellular organisms have responded to a variety of environmental factors such as temperature, pH and mechanical stress. As a result, some of them have evolved to produce absolutely unique biomaterials that only occur in nature," explains Dr Igor Zlotnikov, research group leader at B CUBE - Center for Molecular Bioengineering, who led the study. Minerals produced by living organisms often have structural and crystallographic properties that go far beyond the production capabilities of current synthesis methods.

The team focussed on L. granifera, a type of algae that uses calcite to form shells. Its spherical shells have a unique crystal architecture. The crystals are radially oriented, meaning that they grow outwards from the centre of the sphere. „With today's production methods for perovskites, such materials cannot be produced synthetically. However, we can try to convert the existing natural structures into functional materials while preserving their original architecture," adds Dr Zlotnikov.

Chemical tuning

In order to convert the natural mineral shells of the algae into functional perovskites, the team had to exchange chemical elements in the calcite. To do this, they adapted a method developed by their co-operation partners at the AMOLF Institute in Amsterdam. During the transformation, the scientists were able to create different types of crystal architectures by changing the chemical composition of the material. In this way, they were able to fine-tune the electro-optical properties.

By transforming the calcite shells into lead halides with iodine, bromide or chloride, the team was able to produce functional perovskites that are optimised to emit only red, green or blue light.

Ready for scaling up

„We show for the first time that minerals produced by unicellular organisms can be transformed into technologically relevant functional materials. Instead of competing with nature, we can benefit from their years of evolutionary adaptation," says Dr Zlotnikov.

The method developed by his team can be applied on a larger scale and opens up the possibility for industry to use algae and many other calcite-forming unicellular organisms to produce functional materials with unique shapes and crystallographic properties.

Promotion

The project was part of the DinoLight initiative funded by the Free State of Saxony to develop innovative, environmentally friendly materials and technologies based on naturally occurring three-dimensional nanostructures

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News of the "Technische Universität Dresden" from 13 March 2023