Preparation and characterization of a layered perovskite-type organic–inorganic hybrid compound based on (C 6H 4) 2N (CH 2) 6NH 3Cl

Abstract

The organic–inorganic hybrid compound ((C 6H 4) 2N(CH 2) 6NH 3) 2PbCl 4 (N6AHMC–PbCl 4) and ((C 6H 4) 2N(CH 2) 6NH 3) 2PbCl 2I 2 (N6AHMC–PbCl 2I 2) were synthesized by treating N-6-aminohexamethylcarbazole chloride (N6AHMC–HCl) with stoichiometric amount of PbX 2 (X = Cl, I) at room temperature using dimethylformamide (DMF) as solution. High order diffraction peaks corresponding to (0 0 l) ( l = 2, 4, 6, …) were observed in the X-ray diffraction profile of N6AHMC–PbCl 4 and N6AHMC–PbCl 2I 2, indicating the formation of hybrid crystal with layered perovskite structure. N6AHMC–PbCl 4 presented characteristic absorptions of PbCl-based layered perovskite centered at about 329 nm. Similar to the PL spectrum of N6AHMC–HCl, the film of N6AHMC–PbCl 4 showed three strong emission peaks, indicating that the exciton emission of the N6AHMC–PbCl 4 film comes from the organic layer of the hybrids. Owing to the partially replacement of Cl − with I −, the fluorescence quenched N6AHMC–PbCl 2I 2 showed broad absorption at about 400 nm, which is assigned to the transition from the hybrid orbital hybridized by Cl 3p and I 5p valence states to Pb 6p conduction bands. For the reason of the variation of the energy band structure, from type I quantum well structure to type II heterojunction, the photoconductivity of N6AHMC–PbCl 2I 2 is higher than that of N6AHMC–PbCl 4.