Electrical conductivity of polycrystalline CuInSe2thin films

Abstract
CuInSe2 films with different compositions around stoichiometry have been deposited by coevaporation of Cu, In and Se. In p-type films the electrical conductivity is largely dependent on the Cu-In percentage ratio and increases from 10-6 to 102 S cm-1 when the ratio increases from 0.66 to 1.58. The thermal activation energy is also correlated to this ratio, and decreases from 0.36 to 0.009 eV. The results are analogous to those obtained in polycrystalline silicon and are qualitatively explained by the grain boundary carrier trapping theory.