Influence of the shallow impurity environment on the luminescence of single-quantum dots

✍ Scribed by Arno Hartmann; Yann Ducommun; Manuel Bächthold; Eli Kapon

• Book ID: 104429670
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 345 KB
• Volume: 7
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00372-0

✦ Synopsis

The evolution of low-temperature photoluminescence (PL) spectra of single GaAs=AlGaAs quantum dots (QD) is studied as a function of laser excitation power. At very low powers, where multi-exciton occupation of the QD can be excluded, an unexpected and pronounced spectral evolution is observed. In this weak excitation regime, a signiÿcant di erence in the ÿne structure of single-QD spectra is observed not only among di erent, structurally identical QDs of the same sample, but also among spectra taken from the same single QD excited above and below the AlGaAs barrier. A time-resolved, two-color pump and probe PL experiment on a single QD indicates relaxation times between the di erent spectral shapes in the ms-range. A model, taking into account the in uence of the shallow impurities in the environment of each QD, explains the experimental results.