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Photoluminescence of Si nanocrystals embedded in SiO 2 : Excitation/emission mapping
Author(s) -
Vaccaro L.,
Spallino L.,
Zatsepin A. F.,
Buntov E. A.,
Ershov A. V.,
Grachev D. A.,
Cannas M.
Publication year - 2015
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/pssb.201451285
Subject(s) - photoluminescence , luminescence , excitation , nanocrystal , materials science , exciton , quantum dot , photoluminescence excitation , annealing (glass) , molecular physics , emission spectrum , laser , range (aeronautics) , optoelectronics , spectral line , optics , nanotechnology , condensed matter physics , chemistry , physics , quantum mechanics , astronomy , composite material
Time‐resolved photoluminescence from Si nanocrystals produced by 1100∘ C thermal annealing of SiOx /SiO2 multilayers were investigated by tunable laser excitation, achieving a detailed excitation/emission pattern in the visible and UV range. The emission lineshape is a gaussian curve inhomogenously broadened because of the size distribution of Si nanocrystals, the excitation spectrum consists of the overlap of two gaussian bands centered around 3.4 and 5.1 eV. The mapping of luminescence spectral components with the lifetime points out the energy cubic dependence of the spontaneous emission rate. These findings are interpreted on the basis of models proposed in literature that associate this luminescence with quantum confinement of excitons or interfacial Si/SiO2 defects.