Thin films of lead iodide decompose under band gap illumination, giving rise to iodine desorption and lead aggregates formation. Mass-spectroscopy, conductivity and photoconductivty measurements have been conducted in order to define the desorbing species and elucidate the dissociation mechanism. Desorption rates of atomic and molecular iodine were measured as functions of the Pbl//2 film temperature in the range of 300-500K, together with its dark and photoconductivity. The results suggest a model whereby the molecular desorption originates from special surface sites and undergoes a transition from a diffusion controlled process to a photohole-concentration dominated process at temperatures above 400K. The experimental results and the proposed mechanism are compared with similar recombination-induced processes in alkali halides.
|Number of pages||11|
|Journal||Semiconductors and insulators|
|Issue number||3 - 4|
|State||Published - 1982|
|Event||Recomb Induced Defect Form in Cryst, Proc of the US -Jpn Semin - Urbana-Champaign, IL, USA|
Duration: 2 Jun 1982 → 5 Jun 1982