Researchers from the Ningbo Institute of Materials Technology and Engineering (NIMTE), led by Prof. Ye Jichun, have developed a groundbreaking multifunctional cage-like diammonium chloride molecule. This innovation significantly reduces interfacial energy losses in perovskite/silicon tandem solar cells (TSCs), enhancing both their efficiency and stability. The findings were published in the esteemed journal Nature Communications.
TSCs have gained traction within the photovoltaic sector due to their potential for high efficiency and cost-effectiveness. The theoretical efficiency limit for these cells stands at an impressive 45.1%, yet current technologies still have considerable room for improvement, particularly concerning wide-bandgap perovskite top cells. One of the main challenges hindering progress is the considerable interfacial energy loss occurring at the perovskite/electron-selective contact interface.
To overcome this issue, the research team synthesized the innovative cage-like diammonium chloride molecule. By integrating this molecule into the perovskite/C60 interface, they were able to reduce film defects and adjust the interfacial dipole, effectively minimizing energy losses during operation.
In their experiments, the team produced 1.68 eV perovskite solar cells, achieving remarkable power conversion efficiencies (PCEs) of 22.6% for devices with a 0.1 cm2 active area and 21.0% for those with a 1.21 cm2 active area. When these optimized perovskite top cells were incorporated into a 1.0 cm2 monolithic perovskite/silicon tandem device, the team achieved a PCE of 31.1%.
The tandem device also demonstrated impressive long-term operational stability, retaining 85% of its initial efficiency after 1,020 hours of continuous maximum power point tracking under ambient conditions. This advancement addresses a critical interface challenge in solar cell technology and sets the stage for the further development of efficient and stable perovskite-based tandem photovoltaic systems.
The successful integration of this new molecule not only enhances the performance of TSCs but also provides a significant step forward in the quest for more sustainable and effective solar energy solutions. As the renewable energy sector continues to evolve, such innovations will play a pivotal role in shaping the future of photovoltaic technology.
