Investigation of lattice defects by means of their drift under electric field

Copper and silver related local centres in US crystals were investigated by means of technique based on drift of defects in external electric field. The impurities were first introduced in crystals and then extracted from them under electric field 100-300 V/cm at 600-750 K. Acceptors Cu-Cd and Ag-Cd responsible for emission bands 1000 and 610 nm correspondingly were found to be the only local centres created after impurity incorporation. Local centres related to interstitials Cu-i and Ag-i were not revealed. Different photo-enhanced defect reactions were observed in the crystals before and after impurity incorporation. A transformation of the type of reaction as a result of impurity incorporation took place. (C) 2001 Elsevier Science B.V. All rights reserved.