Polaron Interaction in InAs/GaAs Quantum Dots and Resonant Photoluminescence

✍ Scribed by M. Bissiri; G. Baldassarri H.v.H.; M. Capizzi; V.M. Fomin; V.N. Gladilin; J.T. Devreese

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 100 KB
• Volume: 224
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/(sici)1521-3951(200104)224:3<639::aid-pssb639>3.0.co;2-1

✦ Synopsis

In an adiabatic approach, the efficiency of the electron-phonon interaction (EPI) can be determined by measuring the ratio between the intensities of two of the phonon replicas that EPI induces in photoluminescence (PL) spectra. In low-dimensional structures such as InAs/GaAs quantum dots (QDs), this ratio depends on the excitation energy E exc . Moreover, the evolution of the PL spectra intensity and lineshape with E exc is quite elaborate. We reproduce well this evolution for E exc ranging from far below to above the GaAs bandgap by introducing an effective Huang-Rhys factor S, a commonly used measure of EPI. Nevertheless, the value of S remains much higher than predicted in an adiabatic model, which can hardly account for the reported dependence of S on QD size and shape. The likely source of this lack of consistency is briefly discussed.