Hole conductivity estimation in lead iodide film through kinetic study of tarnishing reaction

Hole conductivity values in compact and adherent PbI2 film grown on Pb have been estimated from the isothermal parabolic rate constants through tarnishing study of pure lead in iodine atmosphere following the inverse procedure of Wagnerʹs tarnishing/scaling equation. Iodide films have been grown inside a specially designed iodination reactor. The investigation has been confined to the temperature and iodine pressure ranges of 423–523 K and 0.615–6.578 kPa, respectively. Estimated hole conductivity values have been found to follow a pressure dependence relation of the type σh• = σh0• pI212 with an associated activation energy value of 66 kJ.mol−1. The iodide film has been characterised by SEM, EDS and XRD analyses.