Intraband carrier dynamics in InAs/GaAs quantum dots stimulated by bound-to-continuum excitation

Abstract

We studied state-filling-dependent intraband carrier dynamics in InAs/GaAs self-assembled quantum dots using two-color photoexcitation spectroscopy. The photoluminescence (PL) intensity was observed to be dramatically reduced by selectively pumping carriers from the intermediate state to the continuum state located above the conduction band edge, and the PL-intensity reduction decreased with an increase in the continuous-wave excitation power. We analyzed the observed state-filling-dependent intraband carrier dynamics by detailed modeling of carrier excitation and relaxation processes in which the two-photon absorption for the interband transition, Pauli blocking, and saturable absorption for the intraband transition is considered.