Electronic conductivity in polyaromatic hydrocarbon glasses:A theoretical perspective

摘要

Based upon Monte Carlo simulations of amorphous molecular glasses,we have computed the electronic structure of five prototypical polyaromatic hydrocarbons using an extended Su-Schrieffer-Heeger model [J.R.Schrieffer,W.P.Su,and A.J.Heeger,Phys.Rev.Lett.42,1698 (1979)].In the presence of excess charges,the resulting potential energy surfaces have been analyzed using Marcus' [Annu.Rev.Phys.Chem.15,155 (1964)] theory of charge transfer to yield reaction coefficients and-via the application of linear response theory-local conductivities.Applying Kirchhoff's rules,the emerging random resistor network problem leads to global conductivities of the order of 10~(-1)-1 S/cm,which correlate with the structural characteristics of the underlying geometry.