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Photoluminescence and AFM Studies on Blue Shifted InAs/Al y Ga 1—y As Quantum Dots
Author(s) -
Duijs E.F.,
Findeis F.,
Zrenner A.,
Bichler M.,
Abstreiter G.
Publication year - 2001
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200103)224:1<47::aid-pssb47>3.0.co;2-t
Subject(s) - quantum dot , photoluminescence , blueshift , annealing (glass) , materials science , atomic force microscopy , optoelectronics , spectroscopy , ground state , analytical chemistry (journal) , chemistry , nanotechnology , atomic physics , physics , chromatography , quantum mechanics , composite material
Photoluminescence and structural properties of self‐assembled InAs quantum dots, grown on Al y Ga 1— y As, are studied for y = 0, 0.3, and 0.5. A maximum blue shift of 150 meV for the ground state emission energy is determined with increasing y for the samples as grown. Increased surface density and size inhomogeneity is observed for growth on AlGaAs compared to growth on GaAs. Rapid thermal annealing at temperatures ranging from 550 to 850 °C is used to further increase the ground state emission energy with respect to the as grown samples. We find a shift up to a maximum emission energy of 1.9 eV for InAs quantum dots (QDs) embedded in Al 0.3 Ga 0.7 As compared to 1.4 eV for GaAs matrix material. To combine the higher spectral shift by annealing for InAs QDs embedded in AlGaAs with the lower dot density for the growth on GaAs, favored for single dot spectroscopy, we investigated InAs QDs grown on AlGaAs separated by 2 ML GaAs. For these samples we observe a maximum shift by annealing up 1.4 eV and intense room temperature PL.