THERMAL EMISSION RATE OF DEEP LOCALIZED STATES IN AMORPHOUS ARSENIC TRISELENIDE

Deep localized-state distribution in amorphous arsenic triselenide thin films has been measured with a modulated photocurrent technique. A peak in the deep localized-state distribution is found at 0.79 eV above the valence-band mobility edge. It is also found that the thermal emission rate of holes from the localized state at the peak is almost constant in the room-temperature range but exhibits thermally activated behavior below and above the room-temperature range. This anomalous temperature dependence of the thermal emission rate is interpreted on the basis of a thermally created defect.