Synthesis,Characterization And Photoelectric Characteristics Of The Lead Manganese Perovskite Materials

Great progress had been obtained in the field of Perovskite Solar Cells?PSCs?in the recent few years.The highest photon-to-electricity conversion efficiency of PSCs has exceeded 22%,which is comparative to that of the crystalline silicon solar cell.The sensitivity of the perovskite materials to the water and oxygen as well as the toxicity of the lead element,however,has limited the application potential of such kind of solar cells.It's thus very important to develop the lead-free solar cell materials with low cost,high efficiency and environmental compatibility.This thesis intends to design synthetic new lead-free perovskite photoelectric functional materials,structure perovskite solar cell device.There is a lot of grain boundary,defects and trap states in polycrystalline perovskite films,making it difficult to determine the intrinsic properties and optical characteristics of perovskite.The method of solvent diffusion is quick and easy for growing single crystal.Here,CH₃NH₃PbI₃ single crystals?MSC?was synthesized by the method of solvent diffusion.Diethyl ether,as an antisolvent,effectively diffused and induced MSC growth by screening different solvents?diethyl ether,tetrahydrofuran,dichloromethane and chloroform?.The structure transform from initial PbI2 to intermediate?HxPbI2+x·xH2O?and finally MSCs was observed by X-ray diffraction.Decomposition of MSCs in aqueous solution was significantly enhanced by potassium iodide coordination and inhibited by CH₃NH₃I?MAI?addition.We ascribed this inhibition behaviours to suppressing MAI migration from the MSC crystal structure.Finally,the optical properties of MSC were studied.Band gap?Eg?for the MSC film is determined to approximately 1.5 eV from diffuse reflectance spectrum and transformed Kubelka-Munk spectrum.The PL peak of the MSCs?776 nm?had a shorter wavelength than the absorption cut-off.This overlap of the PL spectra with the absorption spectrum of MSC allowed photon recycling in thick MSC by reabsorbing the emission.Although the efficiency of CH₃NH₃PbI₃ perovskite solar cell is higher,its structurecontains heavy metal,toxic Pb.If CH₃NH₃PbI₃ perovskite solar cell can be the industry,It is bound to have a greater impact on the environment.It is significance to develop lead-free organic inorganic perovskite and to study its photoelectric properties for theory and practice.Lead free organic inorganic layered perovskite?MA?2MnCl₄ single crystal was synthesized by the method of slow cooling and volatile solvent.The?MA?2MnCl₄ film mainly grown along the?010?,which controlled by TiO2 film.After the device is assembled,the device presented obvious optical current and voltage response.Lead-free perovskite materials is preparing a-CH₃NH₃MnI₃,the film was studied by means of UV-Visible absorption spectrum,found a-CH₃NH₃MnI₃ have consistent with classical perovskite materials?CH₃NH₃PbI₃?absorption properties,but the absorption intensity as the lead of the perovskite is strong,it could also be one of the reasons leads to lower the photoelectric response.Through the preparation of an entire solar cell devices,studies the characteristics of photoelectric device,discovery has obvious photoelectric response,and good stability;Through the test of photoelectric response under different wavelength of light,found 300 nm,460 nm and 530 nm of monochromatic light can be used as a-CH₃NH₃MnI₃ effective wavelength of photoelectric device.At the same time,also has carried on the different solubility test in the solution,analysis are consistent with XRD test result.