Breakdown of the phonon bottleneck effect in self-assembled quantum dots

Spectral and temporal behavior of photoluminescence of site-selectively exc ited InP self-assembled quantum dots were studied in external electric fiel ds. External electric field accelerates the nonradiative relaxation and com peting fast phonon mediated relaxation processes make prominent structures in the static spectra, The spectra agree with the time-resolved spectra aro und the time zero and reflect the phonon relaxation rate. Acoustic phonon m ediated carrier relaxation is much faster than predicted theoretically, The increases of the excitation intensity, temperature, electric current and c harging of quantum dots accelerate the relaxation of the carriers in quantu m dots, indicating build-up of Auger-like processes. This observation demon strates the breakdown of the predicted phonon bottleneck effect not only at the condition for the practical application of the quantum dots but also a t low temperature and under weak excitation.