Time-resolved photoluminescence decay measurements have been performed on samples with varying sized self-assembled InAs/GaAs quantum dot ensembles, formed by substrate mis-orientation alone, but otherwise under identical growth conditions. Ground-state radiative recombination lifetimes from 0.8 to 5.3 ns in the incident energy density range of 0.79 pJcm-2 - 40 nJcm -2 at a temperature of 77 K were obtained. It was found that a reduction of the quantum dot size led to a corresponding reduction of the radiative lifetime. The evident bi-exponential decay was obtained for the ground state emission of the quantum dot array, with the slower second component attributed to a carrier re-capturing and indirect radiative recombination processes. Also experimental evidence of the effect of the AlGaAs barrier in InAs QDs emitting in the wavelength range 1200-1300nm is presented. Time-resolved photoluminescence measurements have been performed on samples with different compositions of Al in the barrier. A full discussion of the lifetimes of these near infra-red emitting dots will be presented.
|Number of pages||9|
|Journal||Proceedings of SPIE - the International Society for Optical Engineering|
|Publication status||Published - 2005|
|Event||Ultrafast Phenomena in Semiconductors and Nanostructure - San Jose, CA, United States|
Duration: 24 Jan 2005 → 27 Jan 2005
- Self-assembled quantum dots
- Time-resolved photoluminescence