Study On Electron Transport Layer And Solvothermal Preparation Of Halogen Hybrid Perovskite Materials

Halogen perovskite materials have excellent photoelectric properties,which have been widely concerned in photoelectric field,especially in photovoltaic field.In recent years,researchers have done a lot of research on them.The production cost and device optimization still need further research.In this paper,the synthesis and control of halogen hybrid perovskite(CH₃NH₃Pb(Br_xCl_1-x)₃)materials were studied,and the electron transport layer(HTL)was constructed by one-dimensional titanium dioxide(TiO₂)nanorod array thin film and zinc sulfide(Zn S)semiconductor materials,which was combined with perovskite materials to explore the preparation process of perovskite based photodetectors.TiO₂/Zn S Composite thin films were prepared by drop-coating method.On the basis of this,TiO₂/Zn S/Perovskite Composite thin films were prepared by drop-coating CH₃NH₃Pb(Br_xCl_1-x)₃,and their properties were tested and analyzed.The main conclusions of this paper were following:(1)TiO₂ nanoarray films with different morphologies were synthesized by hydro-solvothermal method by adjusting different reaction conditions.In deionized water,the morphology of TiO₂ grown on the FTO substrate with the conductive surface facing downward shows a highly ordered nanorods,and the optical and electrical properties are good.TiO₂ nanorods formed in alcohol solvent show a trend of agglomeration.(2)A series of TiO₂/Zn S composite films were prepared by drop-coating method.The optical and electrical properties of the composite film prepared by dropping the mixed solution of 20?L of PFSA Polymer(Nafion),anhydrous ethanol and Zn S were better.Compared with the TiO₂ film without Zn S layer,the composite film had relatively high photocurrent and relatively stable response curve characteristics.In the template group and the reaction time control group,the composite films synthesized at 180°C for 12 h without template showed good photoelectric properties,which indicated that the composite films were more suitable for electron transport layer.(3)Halogen hybrid perovskite(CH₃NH₃Pb(Br_xCl_1-x)₃)materials with different band gaps were synthesized by solvothermal method to regulate the amount of lead acetate and the proportion of halogen.With the increase of lead acetate,the Cl content in the product increased.When the amount of lead acetate is greater than or equal to 40 mg,the crystallinity and purity of the product are higher.With the increase of Cl content,the morphology of the product tends to be small and irregular blocks.The PL emission peak of the synthesized CH₃NH₃Pb(Br_xCl_1-x)₃ crystal can be adjusted from 506.3 nm to 547.8nm,and the corresponding band gap can be adjusted from 2.45 eV to 2.26 e V.(4)TiO₂/Zn S/perovskite composite films were prepared by dropping coating method using the mixed solution prepared by the halogen hybrid perovskite powder.After annealing the perovskite layer,the perovskite grains spontaneously grow to more than 10?m and are loosely distributed on the zinc sulfide layer.The UV-Vis absorption spectrum of the composite films shows that the absorbance curve of each composite film shows a step-like downward trend in the range of 200?800 nm.In the transient light response characteristic spectrum of composite films,the photocurrent curves of all samples are unstable,and the photocurrent intensity is lower than that of monolayer films and bilayer films.