Scientists from the Faculty of Electrical Engineering approached 20 % efficiency with new solar cell technology

Scientists from the Center of Advanced Photovoltaics at the Department of Electrical technology of the Faculty of Electrical Engineering are developing highly efficient solar cells based on hybrid organic-inorganic perovskites. They have now achieved an efficiency of 19.1 %.

Whether organic-inorganic perovskites will become the technology of tomorrow for obtaining cheap electricity from solar radiation will be the result of efforts to resolve the instability of this material. However, this material has already attracted the attention of prestigious magazines mainly because it is easy to manufacture and over ten years of research has outperformed all polycrystalline materials. Traditional production-intensive crystalline silicon technology has not been demeaned yet, but we already know that the future could be about a combination of old and new technology together.

A lot of laboratory work and many skilled people are needed for the development of new technology. One of them is Amalraj Peter Amalathas, a Sri Lankan native, working to improve the efficiency of perovskite solar cells. Amalraj is a member of doc. Jakub Holovský, who, within the CAP (Center for Advanced Photovoltaics) project, led by prof. Tomáš Markvart aims to achieve high efficiency through innovative crystalline silicon technology along with hybrid perovskite technology.

An important achievement on this path is the development of a solar cell with an efficiency close to 20 %, which takes place fully at the premises of Czech institutions - the Faculty of Electrical Engineering of the Czech Technical University in Prague and the Institute of Physics of the Academy of Sciences of the Czech Republic. Although scientists are not trying to compete with the world's best laboratories in raising efficiency, but are more interested in physical principles, their endeavor on a finished component is to verify that they really understand the principles and functions of these components.

The basic material of organic-inorganic perovskite is partly formed by the inorganic lattice PbI₃^–, which, unlike conventional PbI₂, is negatively charged. To do this, the lattice is made up of octahedral cells within which the organic CH₃NH₃⁺ molecules are positively charged. Paradoxically, such a complex system is very easy to set up, but unfortunately it also breaks down easily. The way to greater stability is to use more complex combinations of chemical elements. The main advantage of the material is its remarkable semiconductor quality, especially its very low surface sensitivity.

The research was made possible thanks to the project "Center of Advanced Photovoltaics" Reg. No. CZ.02.1.01 / 0.0 / 0.0 / 15_003 / 0000464 financed by the ERDF.