Thermal ionisation of ground and multiply excited states in InAs quantum dots embedded into InGaAs/GaAs MQW

The photoluminescence (PL) spectra of highly uniform self-assembled InAs quantum dots (QDs) embedded in In 0.15 Ga 0.85 As 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.

[1]  G. Medeiros-Ribeiro,et al.  Electron and hole energy levels in InAs self‐assembled quantum dots , 1995 .

[2]  Cusack,et al.  Electronic structure of InAs/GaAs self-assembled quantum dots. , 1996, Physical review. B, Condensed matter.

[3]  Alfred Forchel,et al.  Optical transitions and carrier relaxation in self assembled InAs/GaAs quantum dots , 1996 .

[4]  Ray-Ming Lin,et al.  TEMPERATURE DEPENDENCE OF PHOTOLUMINESCENCE SPECTRA IN INAS/GAAS QUANTUM DOT SUPERLATTICES WITH LARGE THICKNESSES , 1997 .

[5]  N. Ledentsov,et al.  InAs‐GaAs quantum dots: From growth to lasers , 1996 .

[6]  Fred H. Pollak,et al.  Temperature dependence of the photoreflectance of a strained layer (001) In0.21Ga0.79As/GaAs single quantum well , 1991 .

[7]  Yu. G. Musikhin,et al.  Electronic structure of self-assembled InAs quantum dots in GaAs matrix , 1998 .

[8]  D. Deppe,et al.  Temperature dependence of gain saturation in multilevel quantum dot lasers , 2000, IEEE Journal of Quantum Electronics.

[9]  Andreas Stintz,et al.  Extremely low room-temperature threshold current density diode lasers using InAs dots in In/sub 0.15/Ga/sub 0.85/As quantum well , 1999 .

[10]  D. Bimberg,et al.  InAs/GaAs pyramidal quantum dots: Strain distribution, optical phonons, and electronic structure. , 1995, Physical review. B, Condensed matter.

[11]  N. T. Moshegov,et al.  Capacitance spectroscopy of InAs self-assembled quantum dots embedded in a GaAs/AlAs superlattice , 2000 .

[12]  Luke F. Lester,et al.  Ground-state emission and gain in ultralow-threshold InAs-InGaAs quantum-dot lasers , 2001 .