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 °C for both defect types. Introduction rates were estimated to be 0.1 cm−1 for VIn⋅InI and ∼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 VP vacancies could be found in neither p-type nor n-type materials.