Theoretical Study Of Tuning The Photoelectric Properties Of Iridium(?)and Platinum(?)coordination Complexes By Adding Amidogen Groups

Organic light-emitting devices(OLEDs)have been widely considered for the next generation solid-state lighting and display technology,cause its irreplaceable advantages than other traditional technologies.However,the blue and red light-emitting materials,as the primary color materials of white light display devices,still have some defects to meet the market's requirements for high efficiency,full color display and long operation life devices.Because of the strong spin-orbit coupling effect of the central metal atoms,transition metal coordination complexes have been extensively applied in the field of high efficiency organic phosphorescent materials.Numerous researches have been carried out over decades.In this thesis,two kinds of transition metal coordination complexes with certain good phosphorescent properties were selected,the electron-donating amidogen groups were separately added to the structure of the complex molecules theoretically and the density functional and time-dependent density functional methods were employed to investigate the influences of these modifications.Theoretical calculations on these complexes mainly include structure optimization,molecular orbital energies,vibration frequency analysis,natural bond orbital composition analysis,absorption spectrum at the ground state and phosphorescence spectrum simulation at the lowest-lying triplet state and their phosphorescence efficiencies.The specific research contents are as follows:(1)Adding dimethylamine group to the less focused picolinic acid ligand of FIrpic,a kind of blue light-emitting iridium(?)complexes,for the sake of improving its low phosphorescent emission efficiency and stability.The results show that the introduction of dimethylamine is useful to extend the ?-electron delocalization,increase HOMO energy levels,and enhance hole injection and transfer ability.Furthermore,the phosphorescent quantum yield might be increased by introducing dimethylamine;(2)In order to improve the color purity of the red light-emitting platinum(?)complex Pt N3N-ptb,it was modified by the diphenylamine group.The results indicate that when diphenylamine group added to specific substituion,the emission peak of Pt N3N-ptb would have red shift and the emission efficiency might improve;(3)To explore the influence of ironic sulfides on photoelectric properties,with electronic transmission properties,when used as the substrate of transition metal phosphorescent materials.It is predicted that the transition metal complex would have large interactions with the Fe3S2 parts on ironic sulfides,which may affect the electroluminescence performance of the complexes.The research results of this thesis can provide some references for the designs and syntheses of high-efficiency blue phosphorescent materials and high-purity red phosphorescent materials.In the meantime,the results can pave the way for further research on the utilize ironic sulfide as electron transport materials in electroluminescent devices.