Temporal cross-section for carrier capture by self-assembled quantum dots

✍ Scribed by S. Raymond; S. Fafard; K. Hinzer; S. Charbonneau; J.L. Merz

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 299 KB
• Volume: 53
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/s0167-9317(00)00306-3

✦ Synopsis

Time-resolved studies of the wetting layer photoluminescence is combined with state-filling spectroscopy of the quantum dot emission to obtain carrier transfer rates from the wetting layer to the quantum dot states. This method allows us to obtain the capture rates as a function of wetting layer carrier concentration, a result that cannot be obtained from a time-dependent measurement of the quantum dot emission itself. The results show unambiguously that the capture efficiency increases significantly with the carrier concentration in the wetting layer, indicating the dominant role of Auger processes in the capture dynamics. In the analysis the concept of capture cross section per unit time is introduced to take into account possible changes in capture times for different dot areal densities.