Thermally stimulated current measurements on evaporated PbI2 layers

Thermally stimulated current measurements have been performed on lead iodide layers deposited by vacuum evaporation. In addition to a broad TSC band extending from 120-140K up to 180-200K, several peaks have been observed close to 100K, 170K, 210K and 270K. Comparison of the results with data obtained on PbI 2 samples fabricated by different methods shows a behaviour somewhat different from polycrystalline layers grown in solution and from single crystals. The total concentration of defects reaches 5 x 10 14 -10 15 cm -3 . It is at least one order of magnitude higher than in solution growth layers. It can be noticed that the defect attributed to the lead vacancy is found in evaporated layers as well as in melt grown single crystals while it is not present in solution growth layers.