Abstract
It is shown that bulk nonradiative recombination near the heterojunctions in the wide‐band‐gap regions is probably an important contributor to the higher threshold current densities of the best state‐of‐the‐art molecular beam epitaxial GaAs‐AlxGa1−xAs DH lasers over similar geometry liquid‐phase epitaxial lasers. This recombination probably is at least part of the cause of the large recombination velocity (measured as interfacial recombination velocity) in molecular beam epitaxial heterostructures.