Density Functional Study On Organic Photovoltaic Materials Based On Triphenylamine Derivatives

In this paper,DFT and time-dependent DFT are used to systematically study the following three systems :(1)dye molecules based on triarylamine and quinoline derivatives;(2)dye molecules based on triarylamine and benzothiadiazole derivatives;(3)small molecular hole-transporting materials based on triarylamine.First of all,using density functional theory(DFT)and time-dependent density functional theory(TD-DFT)to study the four kinds of dye molecules based on triarylamine and quinoline derivatives,including the electronic properties,optical properties and intramolecular charge transfer properties.The bond length,the single point energy,the charge distribution,the distribution of electrostatic potential(ESP)and the frontier orbitals were calculated based on DFT theory and B3 LYP functional.The absorption spectra,the minimum excitation energy,oscillator strength,light-harvesting efficiency,fluorescence spectra,the hole-electronic distribution index,HOMO-LUMO charge transfer and the exciton binding energy were calculated based on DFT theory and BHandHLYP functional.The results show that the introduction of alkoxyl into the donor and thiophenyl into the conjugated bridge can improve the optical and charge transfer properties of the dyes.Secondly,using the density functional theory(DFT)and time-dependent density functional theory(TD-DFT)to study the three kinds of dye molecules based on triarylamine and benzene and benzothiadiazole derivatives,including the electronic properties,optical properties and intramolecular charge transfer properties.The bond length,the single point energy,the charge distribution,the distribution of electrostatic potential(ESP)and the frontier orbitals were calculated based on DFT theory and B3 LYP functional.The absorption spectra,the minimum excitation energy,oscillator strength,light-harvesting efficiency,fluorescence spectra,the hole-electronic distribution index,HOMO-LUMO charge transfer and the exciton binding energy were calculated based on DFT theory and BHandHLYP functional.The results show that the optical properties and charge transfer properties of dyes are affected by the composition of conjugated bridge.Finally,using the density functional theory(DFT)and time-dependent density functional theory(TD-DFT)to study the four kinds of hole-transporting materials based on triarylamine derivatives,including the electronic properties,optical properties and hole-transporting properties.The distribution of electrostatic potential(ESP),ionization potential(IP),the frontier orbitals,the hole recombination energy,the hole transfer integral and the hole transfer rate were calculated based on DFT theory and B3 LYP functional.The absorption spectra,the minimum excitation energy,oscillator strength,light-harvesting efficiency and fluorescence spectra were calculated based on DFT theory and BHandHLYP functional.The results show that the introduction of linear electron-withdrawing acetylene bond is beneficial to the improvement of the optical properties and the hole-transporting properties,while the introduction of triarylamine group is not conducive to the improvement of the hole-transporting abilities for molecules.In this paper,a series of organic photovoltaic materials based on trianiline derivatives were studied,and their electronic properties,optical properties and charge transfer properties were systematically studied by DFT theory and TD-DFT theory.It is shown that the electronic properties and optical properties of organic photovoltaic materials based on triphenylamine derivatives can be calculated by density functional theory and time-dependent density functional theory.Therefore,we can apply this theory to the design of organic photovoltaic materials.