Energy relaxation and phonon bottleneck in semiconductor quantum dots

We show explicitly that the so-called phonon bottleneck in energy relaxation in semiconductor quantum dots arises as a limiting case of a more general model originally due to Huang and Rhys [S.V.Goupalov, Phys. Rev. B {\bf 72}, 073301 (2005)]. Therefore, the restrictions on the energy relaxation imposed by the phonon bottleneck are much less fundamental than it is commonly believed. We calculate temperature dependence of the non-radiative multiphonon transition rate within the properly corrected Huang-Rhys model and discuss other models where the phonon bottleneck is circumvented in connection with recent experiments on epitaxial and colloidal quantum dots.