ELECTRIC-FIELD DEPENDENT DIELECTRIC-CONSTANTS IN AMORPHOUS-SEMICONDUCTORS

The electric field dependence of dielectric constants in amorphous semiconductors is obtained theoretically. It can be shown, taking into consideration the lattice thermal energy, that the polarization vector P(s) can exist in different orientations included in a cone. When an electric field is applied, the total energy changes and a new equilibrium is reached. This gives a relationship between field and polarization. A first-order process effect is observed under certain conditions. Some experimental evidence of the field dependence is produced. Finally a method of evaluation of the coefficients involved in the free energy is presented.