Study Of Stability Of Organic-CuCl₂ Hybrids Layered Structure Materials

Hybrid materials with layered perovskite structure represent a new class of materials that may combine desirable physical properties characteristic of both organic and inorganic semiconductor within a single composite class of materials.The inorganic component forms an extended framework bound by strong covalent or ionic interactions to provide high carrier mobility.The organic component facilitates the self-assembly of these materials,enabling hybrids to be deposited by the same simple, low-cost,low-temperature process as the organic materials.The hybrid materials can be used as the semiconducting channel and may be done to maximize both field-effect mobility and current modulation.This promising class of materials offers a variety of exciting technological opportunities.In order to investigate the stability of the hybrid perovskite structure,we fabricated a series of alkylammonium copper chloride hybrid perovskite,(C_4nH_8n+1NH₃)₂CuCl₄ (n=1,2,3)and the perovskite based on 3-(2-Aminoethyl)indole,whose chemical structure was characterized by FT-IR and element analysis.Its thin film was obtained by spin-coating,and X-ray diffraction(XRD)measurements indicated the formation of two-dimensional layered quantum well structure,with the c-axis perpendicular to the substrate surface.The thermal stability of the hybrid materials had been studied by thermogravimetric analysis and differential scanning calorimeter measurements.It was shown that the hybrid materials had a good thermal stability with the decomposition temperature higher than 180℃.Hybrid materials based on linear alkyl amines had from one to three solid-state phase transition and one melting transitions.It decomposed step-by-step(first loss of the organic component,then loss of CuCl₂),and the stability is much better with more carbon chain length.Hybrid material based on 3-(2-Aminoethyl)indole decomposed also step-by-step(first loss of the isolated HCl, then loss of the organic component,and finally CuCl₂). The hybrids were irradiated under UV light to investigate its photo stability.The UV irradiation induced structural variation of the hybrid materials was studied by FT-IR,element analysis,X-ray diffraction(XRD)measurements,UV-vis absorption and photoluminescence.It was shown that under the UV irradition,the layered structure of the hybrid materials((C_4nH_8n+1NH₃)₂CuCl₄(n=1,2,3)and (C₈NH₆-CH₂CH₂NH₃)₂CHCl₄)were not be changed,but the hydrogen bond was much weaker,which induced the change of the charge distribution and the chance of the charge transfer,as well as the resulting the reversible photochromism behavior.