A study of the electron-hole relaxation dynamics in metalorganic chemical vapour deposition (MOCVD)-grown InGaAs/GaAs quantum dots (QDs) emitting at 1.3 μm is presented. The photo-luminescence (PL) rise and decay times are measured as function of carrier density and temperature, showing that the electron-hole relaxation into the QD ground state occurs within a few picoseconds. We find that the emission of two longitudinal optical (LO) phonons is the dominant capture process at room temperature, whereas carrier-carrier scattering dominates the relaxation process at low temperatures and high carrier densities. Finally, the MOCVD-grown QD structures show relatively small PL quenching; the quenching is caused by thermal carrier escape from the QD ground state via absorption of two LO phonons.
Electron-Hole Dynamics in MOCVD-Grown InGaAs/GaAs Quantum Dots Emitting at 1.3 um
DE VITTORIO, Massimo;CINGOLANI, Roberto
2002-01-01
Abstract
A study of the electron-hole relaxation dynamics in metalorganic chemical vapour deposition (MOCVD)-grown InGaAs/GaAs quantum dots (QDs) emitting at 1.3 μm is presented. The photo-luminescence (PL) rise and decay times are measured as function of carrier density and temperature, showing that the electron-hole relaxation into the QD ground state occurs within a few picoseconds. We find that the emission of two longitudinal optical (LO) phonons is the dominant capture process at room temperature, whereas carrier-carrier scattering dominates the relaxation process at low temperatures and high carrier densities. Finally, the MOCVD-grown QD structures show relatively small PL quenching; the quenching is caused by thermal carrier escape from the QD ground state via absorption of two LO phonons.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
