Phonon bottleneck in quantum dots: Role of lifetime of the confined optical phonons

The phonon bottleneck in quantum dots is reexamined theoretically within the intrinsic phonon scattering mechanism. In the coupled-mode-equation formalism, an analytical solution is derived for the carrier relaxation. The result shows that, due to the anharmonic coupling of the confined LO phonon to the bulk acoustic phonons, the carrier relaxation rate is higher than 10¹⁰s^-1 in a wide detuning range of tens of meV around the LO phonon energy, which differs remarkably from the original phonon bottleneck prediction.