Hot carrier relaxation in InAs/GaAs quantum dots

The carrier dynamics in self-organized InAs/GaAs quantum dot (QD) pairs for med in the variable composition amount approach are investigated. Time-reso lved photoluminescence measurements as a function of temperature and of the tunnel-barrier thickness demonstrate the influence of slowed-down intradot carrier relaxation in strongly confined systems. In particular, we demonst rate that the carrier-capture efficiency decreases with increasing temperat ure and find efficient energy transfer between excited states of the QDs. B oth effects are attributed to slowed-down carrier-relaxation in the QDs. (C ) 1999 Elsevier Science B.V. All rights reserved.