Positron annihilation investigations of vacancies in InP produced by electron irradiation at room temperature

Positron lifetime investigations were done on a series of InP samples irradiated to various doses with 2.5 MeV electrons. In n-type materials, positron lifetimes of 265+/-5 and 338+/-15 ps are attributed to indium vacancy-interstitial complexes and divacancy-interstitial complexes, respectively. In p-type materials these defects were not observed. Thermal annealing took place up to 200 OC for both defect types. Introduction rates were estimated to be 0.1 cm(-1) for V-In . In-I and similar to 0.05 cm(-1) for the divacancies. The divacancies showed a temperature dependence of the trapping rate, which suggests a thermally activated process, No evidence for V-p vacancies could be found in neither p-type nor n-type materials. (C) 1997 American Institute of Physics.