The band structure and photoluminescence in a Ge{sub 0.8}Si{sub 0.2}/Ge{sub 0.1}Si{sub 0.9} superlattice with vertically correlated quantum dots
- St. Petersburg State University, Fock Institute of Physics (Petrodvorets Branch) (Russian Federation)
- Russian Academy of Sciences, Institute for Analytical Instrumentation (Russian Federation)
- Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)
- Max-Planck-Institut fuer Mikrostrukturphysik (Germany)
The energy band diagram of the multilayered Ge{sub 0.8}Si{sub 0.2}/Ge{sub 0.1}Si{sub 0.9} heterostructures with vertically correlated quantum dots is analyzed theoretically. With regard to fluctuations of the thickness layer in the columns of quantum dots and to the exciton-phonon coupling, it is shown that the electron states constitute a miniband. The hole wave functions remain localized in the quantum dots. The spectrum of optical transitions calculated for a 20-layered structure at room temperature is in good agreement with the experimental photoluminescence spectrum that involves an intense band at about 1.6 {mu}m. From theoretical considerations and experimental measurements, specific evidence for the miniband in the superlattice is deduced; it is found that the overlap integrals of the wave functions of electrons and holes and the integrated intensity of the photoluminescence band of the Ge quantum dots are described by quadratic functions of the number of the structure periods.
- OSTI ID:
- 21088589
- Journal Information:
- Semiconductors, Vol. 40, Issue 2; Other Information: DOI: 10.1134/S1063782606020205; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7826
- Country of Publication:
- United States
- Language:
- English
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