Two-photon absorption induced anti-Stokes emission in single InGaN/GAN quantum-dot-like objects

We observed crossed transitions and anti‐Stokes emissions in single quantum‐dot‐like objects embedded in the active layer of InGaN/GaN quantum disks by two‐photon absorption techniques. We proposed a phenomenological model based on the interplay between Auger effect and crossed transitions to explain the origin of anti‐Stokes emissions and the preferential excitation of 0D objects at the expense of their surroundings. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) The experimental results of the authors reveal that crossed‐transitions are the key point to understand phenomena related to two‐photon absorption in quantum dot systems. The combined effects of Auger recombination and crossed transitions explain the preferential excitation of 0D objects at the expense of their surroundings and the origin of anti‐Stokes recombination that was observed under two‐photon absorption spectroscopy.