Oxygen is difficult to physically remove in perovskites . Oxygen is excited by light to form free radicals, which further attack the perovskite's crystal lattice. The stability of α-FAPbI3 to δ-FAPbI3 is key to optimizing perovskite solar cells.
Wang Zhaokui and others from Suzhou University used the simple molecule benzaldehyde (BAH). Create a photochemical shield in the perovskite layer. Furthermore, BAH-induced heterogeneous nucleation promoted the crystallization of α-FAPbI3. This greatly improves the stability of the device.
Under air conditions and LED illumination, the target device maintained 95% of the original PCE after 1500 h. The photoelectric conversion efficiency increased from 23.21% of the original device to 24.82% of the target device.
R.-J. Jin, Y.-H. Lou, L. Huang, K.-L. Wang, C.-H. Chen, J. Chen, F. Hu, Z.-K. Wang, Photochemical Shield Enabling Highly Efficient Perovskite Photovoltaics. Adv. Mater. 2024, 2313154.
DOI:10.1002/adma.202313154
https://onlinelibrary.wiley.com/doi/10.1002/adma.202313154