First Principles Study On The Anisotropic Of Charge Mobility Of Organic Molecules

Dued to the rapid development of microelectronic technology, the use of semi-conductor materials is more and more extensive.At the same time,many traditional inorganic semiconductor materials have been discovered insufficient,such as very complex preparation process,preparation condition requirements very harsh and high cost of preparation.In order to solve these problems,scientists continued to study and explore new materials,and finally found that organic semiconductor materials can solve the above problems,which replace inorganic semiconductor materials and become a new type of electronic devices.This kind of material has many advantages,such as the very simple preparation process,low preparation cost,good flexibility,suitable for large area production and utilization.Therefore,Organic semiconductor materials have become the focus of research.In this paper, we use density functional theory in quantum chemistry theory to study the charge mobility and excited state properties of N,N’-butyl-3, 4,9,10-perylenediimide(PDIB).We respectively calculated the migration rate of PDIB and PDIB-2OPh organic molecules and PDIB, PDIB-2OPh,PDIB-4OPh molecular oscillator strength, vertical electric potentials, the vast thermoelectric potentials, vertical electron affinity, the adiabatic electron affinity properties,at the same time, drew the absorption spectra of three kinds of molecular systems.Firstly, the migration rate of PDIB and PDIB-2OPh is studied, finding that the mobility of these two molecules is larger than the electron mobility.Among,the maximum hole mobility rate of PDIB is 94 times that of the electron maximum mobility rate.Secondly,by comparing the hole mobility of PDIB and PDIB-2OPh molecules,finding in PDIB containing derivatives of benzene,the phenoxy rings play as the role of the reverse current device in the near packed column.Thirdly,by studying the effect of benzene oxygen group on the optical properties of PDIB series,we compared the oscillator strength and absorption spectra of PDIB,PDIB-20Ph and PDIB-40Ph molecules,finding that Oscillator strength gradually weakened with the increase of the phenyl group in the molecular system. At the same time, there is the obvious red shift phenomenon in the absorption spectrum.Lastly,by comparing VIP、 AIP、 VEA、 AEA of PDIB、 PDIB-2OPh and PDIB-4OPh molecules,the value of electron affinity (IP) was found to decrease with the increase of the phenyl group.While for PDIB-4OPh molecules,the ionization potential (EA) not only did not decrease but increase. We suspect that this may be to increase the 4 benzene oxygen based PDIB molecules caused by the space has been reversed,which leading to some changes in the properties of the molecule.From the study of the optical properties of PDIB series, it can be seen that the optical properties of the system are constantly weakened with the increase of the phenyl group in the system.Once again confirmed in the derivatives containing benzene,the phenoxy rings play as the role of the reverse current device in the near packed column.