摘要
A Perovskite is any material with the same type of crystal structure of CaTiO_3,a mineral discovered in 1839[1],with the chemical formula of ABX_3,where A and B are two cations and X is an anion.Inorganic metal trihalide perovskites,CsPbX_3(X=Cl,Br,and I),were synthesized almost 60 years later by reacting PbX_2 and CsX salts in aqueous solutions[2].In the ideal cubic-symmetry structure,the A ions in 12-fold cuboctahedral coordination are much larger than the B ions in 6-fold octahedral coordination.Because perovskite does not possess a close packed anion sub-lattice
A Perovskite is any material with the same type of crystal struc- ture of CaTiO3, a mineral discovered in 1839 [ 1 ], with the chemical formula of ABX3, where A and B are two cations and X is an anion. Inorganic metal trihalide perovskites, CsPbX3 （X = CI, Br, and I）, were synthesized almost 60 years later by reacting PbX2 and CsX salts in aqueous solutions [2]. In the ideal cubic-symmetry struc- ture, the A ions in 12-fold cuboctahedral coordination are much larger than the B ions in 6-fold octahedral coordination. Because perovskite does not possess a close packed anion sub-lattice with flexible bond angles, many types of distortions from the ideal structure can occur including the tilt and distortion of octahedra and displacement of cations out of the centers of their coordination polyhedra, leading to lower symmetries： tetragonal, orthorhombic, rhombohedral and monoclinic. Layered perovskites, also known as two-dimensional perovskites, are formed when thin sheets intrude and separate ABX3 structure. Complexity of both chemical compo- sition and crystal structure often renders great challenges in the synthesis and formation of single crystalline stoichiometric per- ovskite phase without co-existence of undesirable parasitic phases.
