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Title: Excitation spectra of photoluminescence and its kinetics in structures with self-assembled Ge:Si nanoislands

The spectral and time characteristics of photoluminescence associated with the radiative recombination of charge carriers in SiGe/Si(001) multilayer structures with self-assembled Ge:Si islands are investigated. The time dependences of the photoluminescence of Ge:Si islands in a wide range of delay times after the pump pulse are considered at various optical-excitation levels. The photoluminescence-excitation spectra from Ge(Si) islands in the SiGe/Si(001) structures are investigated in the region of band-to-band and subband optical pumping corresponding to various time components in the photoluminescence-relaxation kinetics. A significant difference in the shape of the excitation spectra is revealed for fast (0–100 μs) and slow (100 μs–50 ms) components of the photoluminescence signal from the islands. The significant dependence of the photoluminescence-excitation spectra of Ge(Si)/Si(001) islands on the optical-pump power is shown to be associated with the prolonged diffusion of nonequilibrium charge carriers from bulk-silicon layers to Ge:Si islands at high excitation levels.
Authors:
; ; ; ;  [1]
  1. Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)
Publication Date:
OSTI Identifier:
22469704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 49; Journal Issue: 11; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTRA; CHARGE CARRIERS; DIFFUSION; EMISSION SPECTRA; EXCITATION; GERMANIUM; GERMANIUM SILICIDES; LAYERS; OPTICAL PUMPING; PHOTOLUMINESCENCE; RECOMBINATION; RELAXATION; SILICON; TIME DEPENDENCE