Low-dimensional Sn-based perovskites: Evolution and future prospects of solar cells

The bigger pictureTin (Sn)-based perovskite solar cells (PSCs) have attracted much attention because of their low-toxicity advantages. However, traditional three-dimensional Sn-based perovskites face key bottlenecks such as Sn2+ being easily oxidized and device performance being unstable. Recently, low-dimensional (LD) Sn-based perovskites have been extensively studied because of their high formation energy and good stability, which can fundamentally solve the problems faced by Sn-based perovskites.In this review, we summarized the structural diversity and crystallization kinetics of LD Sn-based perovskites and further elucidated their structure-activity relationship. As the complexity of LD Sn-based perovskite systems increases, the interdisciplinary integration among material synthesis, structural optimization, optical properties, and device physics will be required to achieve improved material properties and higher performance of LD Sn-based PSCs.SummaryLow-dimensional (LD) Sn-based perovskites feature high formation energy and hydrophobicity, which display markedly enhanced air stability and have been extensively explored in LD perovskite solar cells (PSCs). With the ever-growing research of LD Sn-based PSCs, systematic analysis and coordination of the abstruse mechanism of stability are required for preparing high-performance LD Sn-based PSCs. In this review, we first provide a summary of the structural characteristics of LD Sn-based perovskite and focus on the impact of diversiform organic spacer cations on LD Sn-based perovskite structure, carrier properties, and solar cells. Then, we discuss the current understanding of the widespread crystallization kinetics responsible for the improved LD Sn-based perovskite film properties, thereby providing a broad opportunity to generalize the universality of various strategies for solar cell applications. Finally, the current challenges and future research prospects for efficient and stable LD Sn-based PSCs are discussed.Graphical abstract