Functional 2D Phases in Mixed Dimensional Perovskite Photovoltaics

Organic‐inorganic hybrid perovskite solar cells (PSCs) with unique properties exhibit their powerful competitiveness in the photovoltaic field over the past few years. However, the challenges of stability for perovskite devices limit the commercialization and further development. The 2D/3D hybrid structures combine the superior efficiency of bulk perovskites and the superior stability of layered perovskites and gradually get hotspots of the photovoltaic field. In addition, there remains a lack of comprehensive understanding and systematic summary of the function of 2D perovskite attributed to the complex nature of 2D/3D structures. Here, the latest progress of 2D/3D hybrid structures and focus on the functionality of 2D phases in mixed structures and the underlying mechanism from the perspective of their different distributions in the perovskite layer is summarized. Then, the insight and vital factors for overall improvements in the stability of 2D/3D structures are thoroughly discussed. Finally, it is expected that this review will contribute to the present challenges and future research prospects in the photovoltaic industry. 2D/3D hybrid perovskite have behaved great potential. However, there remains a lack of comprehensive comprehension and systematic summary of the functionality of 2D perovskite attributed to the complex nature of 2D/3D structures. Here, the mechanism underlying the various functions of the 2D phase in 2D/3D structure is carefully examined, hoping to serve as a guide for the development of this field in the future.