Proceedings of MATSUS Spring 2025 Conference (MATSUSSpring25)
DOI: https://doi.org/10.29363/nanoge.matsusspring.2025.085
Publication date: 16th December 2024
To achieve higher electricity generation at a low cost, the most substantial impact on the energy generation from solar cells is to make existing technologies more efficient per area. This forms the focus of tandem solar cells, which utilize different photoactive materials with different bandgaps, allowing benefiting from a broader range of the solar spectrum. Recent advances in perovskites have dramatically improved their efficiency, with tandem devices—particularly those using silicon bottom cells—showing great potential for further performance enhancement. However, the phase instability of wide-bandgap perovskite top cells under prolonged operational conditions, including exposure to light and heat, poses a significant challenge. To solve the issue, different approaches will be discussed; grain boundary, bulk of perovskite, and the interfaces with charge transport layers. For example, recently, we addressed this by improving cation interactions within the perovskite lattice, enhancing phase stability under light and heat. Furthermore, improving the optical properties and reducing recombination losses has been key to achieving a certified efficiency of 33.7% in perovskite-silicon tandem cells, demonstrating both enhanced performance and operational durability. I will discuss how we are addressing these challenges, utilizing optical spectroscopy and comprehensive analysis techniques.