Lead iodide film deposition and characterization

Lead iodide purification was performed by repeated sublimation at 390°C. Studies of purity and stoichiometry were done by Inductively Coupled Plasma and Differential Scanning Calorimetric methods. These results were compared with those obtained from the same starting material through zone melting purification and with previous reports. Palladium contacts were attached to Teflon substrates with areas of 2 cm ² and lead iodide films 50 to 500 μm in thickness were deposited onto it by sublimation of the purified material at near 390°C. Deposition conditions such as source state (powder, bulk), source-substrate distance and deposition time were optimized. Front palladium thermal deposition contacts and acrylic encapsulation were done on the radiation penetrating surface and electrical properties such as apparent resistivity and current density were measured. The X-ray film detection capabilities were checked by light pulses, X and gamma irradiation. Finally, the film properties were correlated with the starting material, the deposition process and previous data.