Deep Impurity Levels in InP LEC Crystals

Abstract

Deep impurity levels in InP LEC single crystals have been investigated by deep-level transient spectroscopy (DLTS) and photoluminescence (PL) measurements. The effects of heat treatment on DLTS and PL signals have been investigated, the results indicating that a deep impurity level whose emission activation energy is 0.42 eV is closely related to the well-known PL emission band at 1.1 eV. It seems that these DLTS and PL signals originate from a certain complex including P vacancies and defects, since some behaviours of these signals can be well explained by a configuration-coordinate model. Two other deep levels with emission activation energies of 0.31 and 0.60 eV have also been observed. The origin of these deep impurity levels might be due to native defects in the InP LEC crystals.