Theoretical Investigations On Transport Properties Of Different Benzene Derivatives Organic Semiconductor Molecular

The performance of organic thin film transistor,airport effect transistor and organic light-emitting diode is closely related to carrier mobility in organic semiconductor.To obtain high performance electronic devices,it is necessary to obtain the organic semiconductor materials with high mobility.How to obtain efficient organic semiconductor molecules is the challenge of current theoretical calculation.This paper adopts the method based on density functional theory,the new type of the accumulation of organic semiconductor and benzene derivatives molecules structure and intrinsic carrier transport properties in combination with Marcus–Hush charge transfer method for theoretical calculation and analysis of influencing factors.First,introduced in this article USES the simple discontinuous transition model,by using density functional theory and time-dependent density functional theory studies the under neutral state and the charge state of geometry,which can get restructuring,the frontier molecular orbital,vertical ionization potential,electron affinity,and absorption spectra.The migration rate of organic semiconductor molecules was obtained by using Marcus charge transfer theory and Einstein formula.Secondly,the migration properties of PAH1 and PAH2,the isomer derivatives of triphenylene,were studied.The results show that the planarity of triphenylene as the core skeleton also has an effect on the charge transfer mobility of the molecule.In the two triphenyl-derivatives,the plane mobility of PAH2 is higher than that of distorted PAH1,which is 0.143 cm²V^-1s^-1 and occurs at angles of 0°and 180°,showing good p-type organic semiconductor properties.In the two derivatives,the hole mobility and electron mobility values of the compound PAH1 are 0.011 cm²V^-1s^-1 and 0.040 cm²V^-1s^-1 respectively.The distorted core structure results in the migration of the PAH1 less than that of the PAH2.The intermolecular interactions of the two derivatives are analyzed.The face-to-face?-?interaction has a great influence on the charge transfer between adjacent molecules.Finally,the carrier transport properties of four halogenated compounds such as CT,BT,DCT and TCT with tetracene as the core,and tetrabenzofuran derivatives of four cyano substituted derivatives such as CNT,DNT1,DNT2 and DNT3 were investigated.The grouping compares the changes in the single crystal structure and the molecular packing pattern at different positions,different types,and different numbers of substituents,thus theoretically studying the relationship between structure-mobility of organic molecules.Based on the experimentally synthesized crystal model,the relevant parameters of the mobility and their values were calculated theoretically.The energy levels of the front-line molecular orbitals were calculated and the theoretical values obtained were not much different from the experimental ones.This shows that the use of the calculation basis group functionals is reliable and effective.The calculation results show that the hole mobility of the eight derivatives is greater than their respective electron mobilities,which is the same as the experimentally predicted results and shows strong p-type organic semiconductor properties.The hole mobility of a TCT with four chlorine substituents is about twice that of a DCT hole with two chlorine substituents.In addition,the type,position,and number of substituents will affect the structure of the molecule,leading to lower energy levels of the molecular frontier orbitals,suggesting that these derivatives have good stability.The degree of overlap of?-?conjugates in the structure is also one of the factors affecting the migration integral between molecules.The parallel?-?transition model of the layer structure in the crystal structure is more likely to obtain larger mobility.By modifying and modifying organic molecules,more potential organic semiconductor materials are obtained,providing a theoretical basis for experimentally designing and synthesizing more efficient organic molecules.