A cavity model has been developed for the localization of excess electrons in nonpolar media. The assumption of a continuum gives the analytical expression for the potential depth of a cavity, which is mainly determined by the shorthyphen;range repulsive interaction between an excess electron and medium molecules. The shape of the cavity potential can be approximated adequately by a finite spherical well deep enough for the electron localization in alkane glassy matrices. Based on the present model, the broad optical absorption spectra due to the localized electrons in 3hyphen;methylpentane glassy matrix are attributed to boundhyphen;free transitions. The shape and the intensity of the electron spectra observed at 77 and 4.2 K can be reproduced by the theoretical spectra obtained by solving rigorously the spherical well problem. The energy of quasifree electrons, the total energy for the electron localization, and the cavity radius estimated from the simulation of the absorption spectra are in reasonable agreement with the available experimental results.
展开▼
