Photoluminescence excitation spectroscopy of self-assembled SiGe/Si quantum dots
2009 (English)Manuscript (preprint) (Other academic)
Photoluminescence excitation (PLE) experiments are reported for various self-assembled SiGe/Si dot samples grown on Si(001) by molecular beam epitaxy at substrate temperatures ranging from 430 to 580 C. Two excitation peaks were observed, and the characteristics of the involved optical transitions were studied in detail by PLE (in one case implemented together with selective photoluminescence, SPL) on different samples containing either only one SiGe dot layer or multiple SiGe-dot/Si stacks. The temperature- and power-dependence of the excitation properties together with the results of six-band k.p calculations support the assignment of the observed PLE peaks to spatially direct and indirect transitions collected from two different SiGe dot populations.
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IdentifiersURN: urn:nbn:se:liu:diva-53205OAI: oai:DiVA.org:liu-53205DiVA: diva2:287746