Researchers from Helmholtz-Zentrum Berlin (HZB) and other institutions have made a significant breakthrough in the development of perovskite-silicon tandem solar cells, bringing them a step closer to industrial application. Their work, published in the journal Nature, focuses on improving the efficiency of these solar cells through a novel approach involving a cesium chloride (CsCl) seed layer.
Perovskite-silicon tandem solar cells have shown great promise in recent years due to their potential to achieve higher efficiencies than traditional silicon solar cells alone. The researchers at HZB have been at the forefront of this development, and their latest work builds on previous successes in this area.
The team found that the commonly used hole-transporting material, MeO-2PACz, does not cover the textured surface of silicon bottom cells evenly. This uneven coverage leads to the formation of residual lead iodide (PbI2) at the buried interface, which negatively impacts the performance of the solar cells. To address this issue, the researchers introduced a CsCl seed layer. This seed layer promotes the incorporation of organic precursors across the MeO-2PACz/perovskite interface, even in areas with a thin MeO-2PACz layer. This prevents the formation of interfacial PbI2 and results in larger apparent grains, improving the overall quality of the perovskite film.
The practical application of this research for the energy sector is significant. The improved efficiency of perovskite-silicon tandem solar cells means that they could be used to generate more electricity from the same amount of sunlight, making solar power more cost-effective and competitive with other forms of energy. Moreover, the use of a CsCl seed layer is a scalable and industry-compatible technique, which makes it suitable for large-scale manufacturing.
The researchers achieved a certified efficiency of 29.7% with their improved perovskite-silicon tandem solar cells, which is a notable improvement over previous designs. This breakthrough represents an important milestone in the transfer of perovskite-silicon tandem solar cells from the laboratory to the industry, bringing us one step closer to a future powered by clean, renewable energy.
The research was published in the journal Nature.
This article is based on research available at arXiv.