| In this article we discuses the properties of layered organic-inorganic perovskite like compounds based Sni2, which are sorts of the novel functional materials assembly of the organic and inorganic units at molecular scale. The band can be design and tailoring on the molecular scale to form a multi-quantum well structure, which could precise design and control of it electronic properties, shows a great prospect of application in microelectronics and other field. But, so far, the relationship between the structure, energy bands and properties is not clear. The study on relationship of structure-band-properties, between the theory of Knowledge and practical application, from nature at the electronic structure levels has great significance.Ab inito functional theory study on layered organic-inorganic perovskite-type hybrids based on SnI2was carried out with various organic layers and different number of inorganic layer. Dmol3and CASTEP modules of Materials Studio Platform are used to calculate properties of these perovskite-type hybrids, such as energy band structure, the electronic density of states, Mulliken charge, bond energy of organic-inorganic HOMO-LUMO orbits binding energy etc. and calculated carrier concentration of hybrids using energy band of semiconductor model.The results indicate band gap nearby Fermi surface comes from inorganic layers. Top of valance band mainly consist of5s orbits of tin and5p orbits of bridging iodides while bottom of conduct band mainly consist of5p orbits of tin parallel to the inorganic plane and5s orbits of bridging iodides. The tilting of octahedral make the HOMO-LUMO energy make reverse shift, and then larger the band gap. Although The organic layer not influence the band gap directly, the organic parts play a key roles in the forming of hybrids, templating the inorganic layer through interlayer hydrogen bonds. Finally, result of three layered hybrids and3D-inorganic sheets show a great decrease of band gap, and increased carrier concentration. |
PDF Full Text Request