Promoting Thermodynamic and Kinetic Stabilities of FA-based Perovskite by an in Situ Bilayer Structure

• DOI: 10.1021/acs.nanolett.0c00988
• Publication Date: 2020-04-30T21:29:07Z
• Authors: Alex Fan Xu; Na Liu; Fanlong Xie; Tinglu Song; Yue Ma; Pengxiang Zhang; Yang Bai; Yujing Li; Qi Chen; Gu Xu
• Keywords: Formamidinium

The commonly employed formamidinium (FA)-containing perovskite solar cells (PSCs) exhibit a severe phase instability problem, thereby limiting their commercial applications. Here, both stability and energy efficiency of FA-based PSCs were improved by treating the surface with pyrrolidinium hydroiodide (PyI) salts, resulting in 1D structure (PyPbI3), stacked on original 3D perovskite. By employing situ XRD measurements, we revealed that temperature-dependent transition activation barrier was enhanced after forming 1D/3D structure, prolonged time 30-40-fold. From first-principle calculations, found thermodynamic difference between two phases reduced from -0.16 to -0.04 eV stacking PyPbI3, offering additional lifetime improvement. Moreover, champion bilayer PSC exhibits boosted power conversion 19.62%, versus 18.21% control. Such may be enhance photovoltaic performance.