Dark line defect growth in optically pumped AlxGa1−xAs laser material

Abstract

The growth of dark line defects (DLD’s) has been observed in epitaxial AlGaAs wafers under optical pumping. The growth velocity as a function of optical intensity is given by V=AI^1.8. In addition to recombination‐enhanced defect motion, stress‐induced dislocation glide is shown to contribute to the elongation of DLD’s in 〈100〉 and 〈110〉 directions. A climb mechanism may be responsible for the thickening of DLD’s after growth in 〈100〉 directions. The asymmetric growth of DLD’s between 〈110〉 and 〈11̄0〉 directions is attributed to the existence of α and β dislocations and the absence of 90° rotational symmetry in the zinc‐blende structure.