Thiocyanate-Mediated Dimensionality Transformation of Low- Dimensional Perovskites for Photovoltaics

Two-dimensional (2D) hybrid perovskite solar cells have induced widespread research interest owing to their higher stability as compared to three-dimensional (3D) analogues. The photovoltaic performance, however, is still limited. Here, we report a perovskite film dominated by 3D components that are modulated by formamidinium thiocyanate in the 2D PEA(2)FA(3)Pb(4)I(13) perovskite composition. We demonstrate that a dimensionality transformation from a 2D/3D to predominantly 3D perovskite phase in the presence of SCN-based treatment enhances the optical absorption in visible and near-infrared regions. As a result, the power conversion efficiency improved 4.5 times with respect to the control to above 14%. The unencapsulated cell exhibited excellent moisture stability during the shelf lifetime measurement over 70 days under ambient conditions.

Automated summary

By modulating the structure of the perovskite film using formamidinium thiocyanate, researchers have achieved enhanced light absorption and improved power conversion efficiency in two-dimensional hybrid perovskite solar cells. The modified film also exhibits excellent moisture stability, making it a promising candidate for solar cell applications.