Estimation of ionic conductivity of lead iodide film through tarnishing study

Ionic conductivity values as a function of temperature and iodine pressure in compact and adherent PbI2 film grown on pure Pb have been estimated from the isothermal parabolic rate constants through tarnishing study under short-circuit condition. Iodide films have been grown inside a specially designed iodination reactor in the temperature and iodine pressure ranges of 423–523 K and 0.615–6.578 kPa, respectively. Estimated ionic conductivity values have been found to follow a pressure dependence relation of the type σi = σi0 × PI21/3 associated with an activation energy value of 51 kJ·mol−1. The iodide film has been characterized by SEM and EPMA analyses.