Analysis of complex impedance of p-CuIn3Se5 by impedance spectroscopy

Both complex impedance and electric modulus formalisms are considered to study the contribution of dominant electrical conduction mechanisms in bulk p-type CuIn3Se5 semiconductor. An equivalent electrical circuit has been proposed to explain the impedance results that show semicircle arcs at different temperatures. Two different conduction mechanisms were obtained by fitting the data to Cole-Cole equation. The values of calculated resistances for the “grain” and “grain-boundary” contributions were found to decrease with increasing temperature, in agreement with the Arrhenius law associated with activation energy of 179 meV and 199 meV for the “grain” and “grain-boundary” conduction, respectively. The activation energies for relaxation mechanisms were estimated and compared with those obtained from the analysis of electric modulus.