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Title: Urbach absorption edge in epitaxial erbium-doped silicon

We investigate the dependencies of the photocurrent in Si:Er p-n junctions on the energy of the incident photons. The exponential absorption edge (Urbach edge) just below fundamental edge of silicon was observed in the absorption spectra of epitaxial Si:Er layers grown at 400–600 C. It is shown that the introduction of erbium significantly enhances the structural disorder in the silicon crystal which was estimated from the slope of the Urbach edge. We discuss the possible nature of the structural disorder in Si:Er and a new mechanism of erbium excitation, which does not require the presence of deep levels in the band gap of silicon.
Authors:
; ; ;  [1]
  1. Institute for Physics of Microstructures, Russian Academy of Sciences, 603950, GSP-105, Nizhniy Novgorod, Russia and Nizhniy Novgorod State University, 603950, 23 Gagarin ave., Nizhniy Novgorod (Russian Federation)
Publication Date:
OSTI Identifier:
22413067
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTRA; CRYSTALS; DOPED MATERIALS; ELECTRONIC STRUCTURE; ENERGY GAP; EPITAXY; ERBIUM; EXCITATION; LASER RADIATION; PHOTONS; P-N JUNCTIONS; SILICON