Excitation Spectrum, Relaxation and Coherence of Single Self-Assembled CdSe Quantum Dots

✍ Scribed by A. Hundt; T. Flissikowski; M. Lowisch; M. Rabe; F. Henneberger

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 99 KB
• Volume: 224
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/1521-3951(200103)224:1<159::aid-pssb159>3.0.co;2-g

✦ Synopsis

We report on ultra-narrow, long-term stable emission of single, self-assembled CdSe/ZnSe QDs. The excitation spectrum reveals a spectrally sharp excited state with a lifetime of 1.5 ps, related to the LO-phonon decay. In addition, excitation features due to optical and acoustic phonons are present. A strong increase of the exciton-acoustic-phonon coupling is found. The spin relaxation time is much longer than the exciton lifetime of 250 ps. Under resonant excitation, photon beats from a single QD are seen. Coherence of the purely radiatively damped QD exciton is maintained until it recombines.