An international research network led by Graz University of Technology (TU Graz) is working to increase the stability of organic solar cells.
Organic solar cells are a promising alternative to silicon cells as they are light and flexible. This opens up several opportunities for the renewable energy industry, including the production of emission-free electricity.
Applied to transparent film, they can be used in various geometric shapes and colours in areas for which silicon-based solar cells are unsuitable.
One problem so far, however, has been their short lifespan: these cells deteriorate quite quickly, which is why they are still of little commercial importance.
Under the leadership of TU Graz, the ‘OPVStability’ network brings together international partners from science and industry who will be conducting research over the next four years to increase the durability of organic photovoltaic cells. Funding for the project, which is around €2.7m, will be awarded by the European Commission.
A paper detailing the new research on these solar cells is published in Advanced Materials Science.
Why do organic solar cells decompose so quickly?
“There are thousands of material combinations that can be used to produce organic solar cells,” explained project director Gregor Trimmel from the Institute for Chemistry and Technology of Materials at TU Graz.
“We want to find out which of them are the most suitable, particularly durable, and yet efficient in terms of electricity output.”
The researchers studied the decomposition process of various potentially suitable materials in detail. To do so, the organic compounds are exposed to artificial sunlight in the laboratory and tested under real weather conditions in Europe and the Negev desert.
The precise analysis of the gradual degradation is challenging. Trimmel said: “Organic solar cells are no more than 200 nanometres thick. To be able to isolate decomposition products in them, very special methods and instruments are needed.”
Using Artificial Intelligence to study decomposition patterns
To overcome this difficulty, the researchers are using approaches based on Artificial Intelligence and Machine Learning to analyse the large amounts of data that are generated in high-throughput experiments.
The results of the investigations will allow detailed deductions of the chemical decomposition processes.
In addition to the physical tests, digital simulations of chemical compounds will be run to find the most suitable materials for the next generation of organic solar cells.
