Estimation of electron and hole mobility of 50 homogeneous fullerene amorphous structures (C60, C58B2, C58N2 and C58NB) using a percolation corrected Marcus theory model

Carrier mobility is one of the important characteristics of organic semiconductors. Materials with improved charge mobility are currently in high demand. This study pertains to boron and nitrogen substituted fullerenes, the material with a high potential application in the optoelectronic devices. In our exploration, 50 fullerenes were investigated; 23 isomers of C58B2 and C58N2 and 3 selected isomers of C58BN. The distinguished 23 isomers represent all possible combinations of substitution of two carbon atoms with the same element in C-60. Three C58BN molecules represent isomers in close proximity and at the antipodal positions of the fullerene. Owing to recent advances in computer hardware, large scale quantum chemical and molecular dynamics simulations have become feasible. Charge transport properties calculations were based on the Marcus approximation. Using the density functional theory approach and molecular dynamics simulations, the charge hopping rate as defined in Marcus equation can be obtained. It can further be applied to calculate mobility as proposed by Deng and Goddard together with percolation correction. C58B2 compounds on average have higher charge mobilities than C58N2 ones. Five C58B2 and two C58N2 molecules have better electron mobility than C-60. Many more compounds outperform C-60 for hole mobility. The highest electron mobility is predicted for one of the C58B2 isomers, that is two times higher than that for C-60. For hole mobility, one of the C58BN isomers exhibited mobility that is almost four times larger than that for C-60.