Study On The Synthesis And Luminescence Mechanism Of Low-dimensional Perovskite Materials With Single Component White-light Emission

Low-dimensional perovskites feature the diversity of available ionic compositions and flexible structure,which makes it possible to achieve different properties via doping a certain metal ion or incorporating functional organic molecules into these perovskites.Currently,two common strategies are Mn-doping and chiral-molecule-incorporating.However,to the best of our knowledge,the photoluminescence mechanism under the regulation of defect engineering of low-dimensional organic-inorganic hybrids Mn-doped lead halide perovskite MCs(microcrystals),especially 1D(one-dimensional)mixed Pb–Mn perovskit MCs,is not well understand.Meanwhile,there are no reports about the photoluminescence mechanism of low-dimensional hybrids perovskites with combined chirality and a single component white-light emission.Based on these,in our work,we implemented Mn-doping strategy to synthesize a series of 1D C₄N₂H₁₄Pb_xMn_1-xBr₄ MCs with broadband white-light emission and provided the overall photoluminescence mechanism of 1D C₄N₂H₁₄Pb_1-xMn_xBr₄ MCs for the first time.By the combination of the results obtained from steady-state and ultra-fast spectra,photoluminescence mechanism of these MCs involves competition of FE(free exciton)and STE(self-trapped exciton)and ⁴T₁ states,and further promotes photoluminescence tunability.In order to promote multifunctional application of perovskite materials,we carried out chiral-molecule-incorporating strategy to prepare two chiral 2D perovskites(R-(+)-?-MPEA)₂Pb Br₄ and(S-(-)-?-MPEA)₂Pb Br₄ with broadband white-light emission and studied their photoluminescence mechanism.Moreover,a achiral perovskite((rac)-MPEA)₂Pb Br₄featuring with broadband white-light emission was prepared.The influence of chirality on the properties of the host perovskite was further investigated.Through comprehend analysis of steady-state and ultra-fast spectra for chiral and achiral perovskites,the broadband white-light emissions of these perovskites originate from FE and STE indeed.The existence of chirality makes their properties different.To this end,all as-synthesized perovskite crystals exhibit a single component broadband white-light emission in this thesis,which paves the way towards the investigation and development of optoelectronic application of perovskite materials.Moreover,chiral perovskites with broadband white-light emission combine properties of chiral materials and metal halide perovskites.This will promote development on multifunctional application of white-light emissive perovskite materials.