2D Tin Halide Perovskite Semiconductors: Fundamentals, Applications, and Future Perspectives

Tin (Sn) halide perovskites have emerged as promising lead‐free semiconductors for next‐generation electronic applications due to their non‐toxicity and exceptional optoelectronic properties. Among them, two‐dimensional (2D) layered Sn‐based perovskites incorporating insulating and hydrophobic bulky spacer cations offer distinct advantages over their three‐dimensional (3D) counterparts. These include outstanding structural flexibility, reduced ion migration, enhanced exciton binding energy, and improved environmental stability. To advance the research in this field and enable the development of high‐performance tunable optoelectronic devices, this review provides a comprehensive analysis of the fundamental properties of 2D Sn‐based perovskites, including structure‐property correlations, charge carrier dynamics, operational stability, and synthetic strategies. Then, the recent progress in diverse device applications, namely light‐emitting diodes, field‐effect transistors, and memristors, is critically discussed. Finally, it identifies the key challenges and limitations and provides perspectives to guide future research directions in the design and application of 2D Sn‐based perovskite materials.