Work

Low-dimensional templates and delayed crystallization for high-quality tin-based perovskite films and high-performance transistors

Year: 2025

Type: article

Abstract: The quasi-2D tin-based perovskite is a prominent candidate for p-type perovskite semiconductor materials because of their remarkable thermodynamic stability and diminished ion migration tendencies. However, the competitive growth of low-dimensional and high-dimensional phases in quasi-2D perovskites leads to structural disorder and poor crystal orientation, thereby forming defective films and further impacting charge carrier transport. Here, we introduce a strategy to selectively promote the formation of high-quality PEA 2 FA n − 1 Sn n I 3n−1 SCN 2 (n = 2) templates by incorporating PEASCN into the perovskite precursor solution. By substituting formamdinium iodide (FAI) with formamidinium formate (FAHCOO) and ammonium iodide (NH 4 I), we effectively inhibit the growth of 3D FASnI 3 , thus achieving control over crystallization kinetics. This approach facilitates the growth of low-dimensional templates that guide the formation of high-dimensional phases during the annealing process. The resulting optimized perovskite films exhibit a well-defined vertical crystallographic orientation and reduced defect density, which significantly enhance charge carrier transport. The fabricated field-effect transistors demonstrate a maximum mobility of 43 cm 2 V − 1 s − 1 and an on/off ratio exceeding 10 8 . Furthermore, the unencapsulated devices show outstanding operational and environmental stability, maintaining performance for over 30 days. These results offer new insights into the material engineering of tin-based perovskite films and highlight the potential for high-performance and stable devices.

Source: Nature Communications

DOI: 10.1038/s41467-025-64560-2