Carrier scattering by Auger mechanism in a single quantum wire

We report on time-resolved microphotoluminescence experiments in a single GaAs/GaAlAs V-shaped quantum wire as a function of optical excitation intensity. At low pump power we observe that excitons are localized in quantum boxes formed by the local potential minima existing along the wire axis. As the pump power is increased, state filling of the lowest lying levels of the boxes appears. When two carriers occupy the first excited level of the box, a very efficient Auger scattering occurs, leading to a transfer of carriers from one box to another neighbouring one. The intradot Auger scattering time has been measured and is of the same order of magnitude as the LA-phonon emission rate. PACS. 71.35.-y Excitons and related phenomena – 78.47.+p Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter – 78.66.Fd III-V semiconductors