Study On The Synthesis, Structure Control And Luminescence Properties Of Organic-inorganic Hybrid Metal Halides

In recently years,organic-inorganic hybrid metal halides have attracted extensive attention due to their structural diversity and outstanding optoelectronic properties,which make them promising candidates for LEDs,light-emitting transistors,solar cells,photodetectors,etc.In this thesis,guided by functional-oriented structural design,we selected organic amines with different spatial configurations and electronic configurations as cationic template agents,Pb of?A group and Cu,Ag of IB subgroup as optically active centers toconstruct organic-inorganic hybrid low-dimensional metal halide functional materials.The specific work content and achievements are summarized as followed:?1?We selected N,N'-dimethylethylenediamine?DMEDA?as an organic cation and prepared one new type of one-dimensional?1D?organic-inorganic hybrid material[H2DMEDA]PbCl4?1?by a simple solution method.The PL properties and stability of the compound 1were also investigated.This 1D structure gives a bright yellow emission with photoluminescence quantum efficiency?PLQE?of approximately 4.81%by forming the self-trapped excited states.Furthermore,the white light emitting device can also be easily fabricated by coating the sample of compound 1 on a blue light chip.?2?Based on single metal halide light-emitting materials,we adopt the strategy to introduce the d¹00 trasition mental?TM?Cu⁺or Ag⁺with different electron configurations,which incorporate the TM-X and Pb-X bonding in hybrid heterometallic halides with more flexible structural building units and organization manners.Here,we selected the same orgnic amine 1,4-diazabicyclo[2.2.2]octane?DABCO?as template and took the solvothermalmethod,by introducing heterometals as mixed structural compositions and optical activity centers,we prepared a series of low-dimensional hybrid heterometallic halides,namely as,[?Me?-DABCO]₂Cu₂PbI₆,[?Me?₂-DABCO]₂M₅Pb₂I₁₃?M=Cu and Ag?and[?Me?₂-DABCO]Ag₂PbBr₆?Me=methyl group?.Under the photoexcitation,these hybrid heterometallic halides exhibit deep-red luminescent emissions from 711 to 801 nm with the largest Stocks shift of395 nm.This work affords a new design strategy to prepare red to near-infrared PL materials.?3?Based on lead hybrid halides,we selected the non-toxic group IB metals Ag⁺as optically active metal center instead of Pb²⁺,we prepared three kinds of Ag-based organic-inorganic hybrid metal halides[H₂DABCO][Ag₂X₄?DABCO?]?X=Br?6?,I?7??and[HDABCO]₃Ag₅Cl₈?8?.Compound 6 exhibits an efficient broadband white-light emission with photoluminescence quantum efficiency?PLQE?of about2.1%and excellent photochemical stability.This work provides a unique structural assembly method to explore lead-free single-component white-light illuminants.