Trapping States Formed by Structural Defects in Molecular Crystals

Abstract

Abstract Results of calculations of the energetic distributions of trapping states in simple molecular crystals are given in the paper. A crystal with primitive regular unit cells has been taken into account, and three kinds of simple isolated linear defects have been considered: an edge dislocation, a linear array of vacancies, and a defect formed by a linear array of molecules larger than the host ones. Equilibrium positions of molecules in the vicinity of the defects have been calculated describing the intermolecular interactions by the Lennard-Jones type potential function. Local values of the polarization energy and hence depths and distributions of traps formed by molecules neighbouring to the defects have been calculated in the ion-dipole approximation. It has been shown that the formation of trapping states by thermal vibrations can be neglected as being a small effect.