First-principles Of Electronic Structure For Layered Perovskite-type Organic-inorganic Hybrids

Layered perovskite-type hybrids, assembling with organic and inorganic components at the molecular scale, are a family of natural quantum well materials. Due to their unique tunable structure and controlled property, such materials have a great potential in many practical applications. By building the related structural models, detailed and systematic electronic property of the resulting structures has been carried out to gain fundamental insight into key relations between component-structure-bands-properties.Based on the ab inito concentration functional theory, a serial of hybrid perovskite structures, such as (C4H9NH3)2MI4(M=Ge,Sn,Pb),(NH3C6H12NH3)MI4(M=Ge,Sn,Pb),(RNH3)2(CH3NH3)n.1MnI3n+1(M=Sn,Pb;n=1,2,3),(CnH2n-1NH3)2PbI4(n=3,4,5),(C6H5C2H4NH3)2MI4(M=Ge,Sn,Pb),(CnH2n+iNH3)2PbI4(n=4-10,12,14,16,18),(CH3C6H4CH2NH3)2PbI4,(C6H5CH(CH3)NH3)2Pbl4,(NH3C6H12-NH3)PbI4and (NH3CgH14NH3)PbI4were built, and the relationship among electronic properties, organic and inorganic layers, metallic elements were systematically investigated.Our work mainly focus on:(1) the electronic concentration of states, Mulliken charge, energy band structure, bond energy of organic-inorganic layered perovskite-type hybrids were calculated based on first principles calculation method;(2) the carrier concentration of layered perovskite-type hybrids was calculated by energy band of semiconductor model;(3) the difference of the physical properties (e.g. DOS, Mulliken charge, the carrier concentration, band structure) of the organic-inorganic hybrids and the physics origin of them were analyzed. The influencing factors on the carrier concentration with the sort of the inorganic and organic layers have been established.In this paper, it can be found that the band gap nearby Fermi surface comes from inorganic types and layers. Comparing with germanium iodide and lead iodide system, the tin iodide was found that it can increase the carrier concentration of the metal into semiconductor. Based on the same organic unit, the band gap of tin iodide-based hybrids is the lowest than those of lead-based and germanium-based hybrids. In this case, the band gap is up to1.080eV while their carrier concentration reach4.389x109cm-3. Increasing the number of inorganic layers, the hybrids transition from semiconductor to metal. When the inorganic layers are up to3, the carrier concentration of layered perovskite-type hybrids can reach3.479×1015cm-3.The organic species have no the direct influence to the band gap of any hybrids. However, the organic units play a key role owing to the interaction between inorganic metal and organic unites. The hydrogen bond between organic and inorganic components have an effect on the inorganic layer to deviate from the ideal cubic perovskite framework, leading to the inorganic layer in the M-I bond lengths and M-I-M bond angle changes, causing the octahedral structure distorted, and increasing the inorganic layer band gap, and changing carrier concentration. Generally, layered perovskite-type hybrids, integrated inorganic metal and organic unites would be exhibit desirable physics properties by tuning their components and structure which aim to develop an effective approach towards excellent and flexible semiconductor materials.