Structurally Dimensional Engineering in Perovskite Photovoltaics

The low‐dimensional (LD) perovskites are proven to be capable of blocking moisture erosion and thereby improving the photovoltaic device stability. In this review, the low‐dimensional (LD) perovskite materials are carefully summarized that are induced by A‐position organic substituents, starting from the crystal microstructure and electronic structure of LD (2D, 1D, and 0D) perovskite materials with regulating dimensions, combined with first principles calculation (DFT). By further studying the thermodynamics and dynamics of crystallization nucleation and growth of LD–3D perovskite thin films in the heterojunction region, LD–3D heterojunction perovskite thin films and solar cells with controllable dimensions can be in situ prepared. Various LD–3D perovskite structure photovoltaic devices are systematically summarized, which shows flexible regulation of the energy band structure and carrier transport characteristics, locks the water oxygen corrosion channel with close‐fitting conjugated structure, and improves the long‐term stability of the LD–3D perovskite solar cells. This review is expected to provide some guidance for the perovskite development and multipurpose use through in depth understanding of the structurally dimensional engineering in perovskite photovoltaics. The low‐dimensional (LD) perovskite materials induced by A‐position organic substituents are summarized in detail, focusing on the crystal microstructure of LD‐perovskite materials with tunable dimension and electronic structure based on first‐principles calculations density functional theory. Various LD–3D perovskite structure photovoltaic devices are also systematically summarized, which is expected to provide some guidance toward addressing the long‐term stability issues of perovskite solar cells and beyond.