The thermoelectric power, the dark electrical resistivity and the grain boundary potential barrier in CdIn2Se4 thin films

The thermoelectric power (Seebeck coefficient S) was measured for several preannealed CdIn2Se4 thin films of different thicknesses. The thermoelectric power measurements indicate that the preannealed CdIn2Se4 thin films are n-type semiconductors. The thermoelectric was utilized to calculate the free charge carrier concentration in the temperature range of 298–453 K. Measurements of the dark electrical resistivity for samples of different thicknesses as a function of temperature in the temperature range of 298–423 K were analyzed to give the thermal activation energy of the free charge carriers. The free charge carrier concentration calculated from the thermoelectric measurements for each sample in connection with the sample conductivity at a given temperature were used to calculate the free charge carrier mobility from which the grain boundary potential barrier was evaluated. It was found that the grain boundary potential barrier plays a distinguishable role in the behaviour of the dark electrical conductivity