The effect of temperature on photoinduced metastability in avalanche a-Se layers

The effect of temperature on the initiation of light-induced defects in a-Se targets of high-gain avalanche rushing photoconductor (HARP) camera tubes was studied. At room temperature, avalanche a-Se was found to be subject to both reversible and irreversible photodarkening. At 35 °C, the irreversible photodarkening component was completely absent. This result is attributed to the instantaneous annealing of light-induced metastable coordination defects at elevated temperatures. A model for the formation of permanent crystalline areas at low temperatures via transition states associated with light-induced metastable defects is proposed.