Electrical conductivity and crystallization kinetics of amorphous Se0.81In0.19 films

Abstract

The temperature dependence of the DC conductivity (σ) of amorphous Se and Se0.81In0.19 thin films, prepared by thermal evaporation, has been studied. The incorporation of In atoms in a Se matrix leads to an increase in the electrical conductivity of Se0.81In 0.19 and to a decrease in the thermal activation energy of conduction from 0.57 to 0.24 eV. The change in σ with time during the amorphous-to-crystalline transformation is recorded for Se0.81In 0.19 films at different isothermal temperatures in the range 343-373 K. The results indicate that the micro-heterogeneous structures of the films have a remarkable influence on the electrical conductivity during the amorphous-to-crystalline transition. The formal crystallization theory of Avrami has been used to calculate the kinetic parameters of crystallization. The activation energy of the amorphous-to-crystalline transformation is found to be 0.82 and 1.29 eV, respectively, for the two stages of crystallization during the time period of the transformation process. © 2005 Elsevier B.V. All rights reserved.