Author/Authors :
Torchynska، نويسنده , , T.V. and Casas Espinola، نويسنده , , J.L. and Velلsquez Losada، نويسنده , , E. and Eliseev، نويسنده , , P.G. and Stintz، نويسنده , , A. and Malloy، نويسنده , , K.J. and Pena Sierra، نويسنده , , R.، نويسنده ,
Abstract :
The photoluminescence (PL) spectra of highly uniform self-assembled InAs quantum dots (QDs) embedded in In0.15Ga0.85As multi-quantum-well (MQW) heterostructures have been investigated at variable temperatures. This paper presents the PL bands, connected with ground (GS) and multi-excited states (ES) in QDs. Not equidistant optical transitions have been revealed. Spectral peak shifts and PL intensity variations in the temperature range 12–220 K for all PL bands are analyzed. The activation energy of the temperature quenching processes for GS and 4 ES optical transitions in InAs QDs are measured. The mechanism of these processes and the positions of the energy levels in QDs are discussed as well.
