Functionalized Polymer-Capped SnO₂ Nanoparticle Electron Transport Layer for Efficient Perovskite Solar Cells

For the last decade, perovskite solar cells have been in rapid growth, highlighted as a representative next-generation solar cell. Although SnO₂ is suitable as the electron-transporting material of perovskite solar cells, there also have been some obstacles in the formation of uniform and thin layers of SnO₂ on the uneven FTO substrate. In this work, we investigated polymer-assisted fabrication methods to achieve conformal coating of SnO₂ nanoparticles on rough FTO substrate, finally leading to improved performance of perovskite solar cells due to enhanced coverage and optimized electron-transporting property. As a result, we fabricated an efficient perovskite solar cells with a power conversion efficiency of 24% by employing polymer-capped SnO₂ nanoparticles as electron-transporting layer.