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Raman Scattering in GaN/AlN Quantum Dot Structures
Author(s) -
Gleize J.,
Demangeot F.,
Frandon F.,
Renucci M.A.,
Kuball M.,
Widmann F.,
Daudin B.
Publication year - 1999
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/(sici)1521-3951(199911)216:1<457::aid-pssb457>3.0.co;2-8
Subject(s) - quantum dot , uncorrelated , raman scattering , materials science , condensed matter physics , excitation , scattering , phonon , strain (injury) , matrix (chemical analysis) , raman spectroscopy , optoelectronics , optics , physics , quantum mechanics , composite material , medicine , statistics , mathematics
The strain field in the surrounding AlN matrix of GaN quantum dot layers, vertically stacked along the [0001] growth direction, is studied through its effects on the AlN E 2 phonon frequency. Comparison is made between a structure composed of large, vertically correlated quantum dots and a less densely stacked system of smaller, uncorrelated dots. We find evidence for a mean extensive strain state of the AlN matrix in the former structure associated with local strain favoring the vertical alignment of the dots. Scattering by the A 1 (LO) phonon of the uncorrelated smaller dots is observed under resonant conditions when using a laser excitation approaching the fundamental transition energy of the quantum dots.