The possibility of generating renewable electricity at a low cost through organic solar cells has become more plausible due to recent breakthroughs. However, the long-term stability of these carbon-based semiconductor solar cells still poses a challenge for practical application. Therefore, a team of international researchers led by the University of Cambridge’s Cavendish Laboratory set out to investigate the degradation mechanisms of the electron donor and acceptor materials, which are crucial for converting photons into electrical current.
The team’s research, published in Joule, is a significant advancement in the field of organic solar cell technology. They identified an ultrafast deactivation process unique to the electron donor material, providing new insights into material degradation. The researchers used photovoltaic device stability studies and ultrafast laser spectroscopy to identify a new degradation mechanism in the electron donor material, which involves twisting in the polymer chain. This causes a rapid deactivation process when the twisted polymer absorbs a photon, reducing the efficiency of the solar cell.
Dr. Alex Gillett, the lead author of the study, emphasized that the seemingly minor twisting of the polymer chain has a significant impact on solar cell efficiency. The team intends to work together with chemistry groups to develop novel electron donor materials that have more inflexible polymer backbones. This will help in decreasing the inclination of the polymer to twist, leading to an enhancement in the stability of organic solar cell devices.
Organic solar cells have unique properties that make them suitable for a wide range of applications. For example, they can be used to create electricity-generating windows for greenhouses that transmit the necessary light for photosynthesis. They can also be used for mobile electricity generation, as they can be rolled up for easy transportation. Therefore, identifying the degradation mechanism that needs to be addressed brings us closer to the next generation of photovoltaic materials and applications.
The discovery made by the international team is a significant step towards the development of stable organic solar cells, which could revolutionize the field of renewable energy. The research provides a new understanding of how electron donor and acceptor materials degrade and suggests new strategies for designing more stable organic solar cells. With further research and development, this technology could offer a cost-effective and sustainable solution for meeting the world’s energy needs.