Boosting Tin-Based Solar Cells with a Smart Interface Trick

Tin-based perovskite solar cells (Sn-PSCs) have a problem. The material used to help transport charges, PEDOT:PSS, isn't doing a great job. It's not stable, and it doesn't work well with the tin perovskite. This is because of some issues with how they interact at the molecular level. But there's a clever solution on the horizon. A special molecule, called 2PADCB, is stepping in to fix these problems. This 2PADCB molecule is part of a group known as self-assembled monolayers (SAMs). It has a unique structure that helps it stick to the PEDOT:PSS surface. It does this by reacting with a part of the PEDOT:PSS molecule. This reaction also helps to reduce some of the issues caused by the PSS part of PEDOT:PSS, like making the surface too acidic and reducing conductivity. But that's not all. The 2PADCB molecule also has a special terminal group with two benzene rings. These rings increase the electron density around the tin ions, which helps to prevent them from oxidizing. This is a big deal because oxidation can mess up the performance of the solar cell. Plus, the 2PADCB molecule is hydrophobic, which means it repels water. This is important because water can cause the tin perovskite to degrade over time. So, what does all this mean for the solar cells? Well, when 2PADCB is added to the PEDOT:PSS layer, the solar cells perform better. They reach a higher efficiency of 14. 7%, compared to 12. 5% without the 2PADCB. But more importantly, they also last longer. The solar cells maintain 90% of their initial efficiency after 160 hours of continuous use. This is a significant improvement and shows that the 2PADCB molecule is doing its job. The reason for this boost in performance and stability is the improved interface between the PEDOT:PSS and the tin perovskite. The 2PADCB molecule helps to create a better connection, which leads to improved charge transport and reduced charge recombination. This means that the solar cells can convert more sunlight into electricity and do so more efficiently. This is a promising development for tin-based perovskite solar cells. By introducing the 2PADCB molecule at the interface, it's possible to create more efficient and stable solar cells. This could be a big step forward in the world of solar energy, as researchers continue to look for ways to make solar cells more effective and long-lasting.