No abstract

We have observed efficient photoluminescence upconversion in semi-insulating GaAs. This upconversion is apparently associated with a two-step excitation of the deep level EL2 as indicated by the excitation spectrum. Assessment of these results along with results in the literature suggests that this center is due to an arsenic antisite defect. Line shape analysis indicates that clustering of acceptors occurs near the site of the defect. These results provide insight into the agents responsible for the semi-insulating property of undoped GaAs.

No abstract

No abstract