Low-dimensional perovskite modified 3D structures for higher-performance solar cells

For solution prepared perovskite solar cells, metal halide perovskite materials with low-dimensional (LD) are flexibly employed in 3D perovskite solar cells to promote efficiency and long-term stability. In this review, the various structures, properties, and applications of LD perovskites are firstly summarized and discussed. To take advantage of LD materials, LD perovskites are introduced in the 3D bulk and/or the interface between the perovskite thin film and the carrier transporting layer to passivate the gain boundary defects while providing the stability advantage of LD materials. Therefore, the preparation methods and crystallization control of the LD perovskite layers are discussed in depth. Then, the combined devices using both LD and 3D components are reviewed on the basis of device design, cell structure, interface charge transfer, energy lever alignment, and synergistic improvement of both efficiency and stability. Finally, the challenges and expectations are speculated for further development of perovskite solar cells.