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Biaxial stress‐induced giant bandgap shift in BiFeO 3 epitaxial films
Author(s) -
Fu Z.,
Yin Z. G.,
Chen N. F.,
Zhang X. W.,
Zhang H.,
Bai Y. M.,
Wu J. L.
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201105500
Subject(s) - materials science , band gap , epitaxy , stress relaxation , stress (linguistics) , relaxation (psychology) , condensed matter physics , composite material , optoelectronics , layer (electronics) , linguistics , philosophy , psychology , social psychology , creep , physics
Thickness‐dependent stress relaxation and its influence on the bandgap of BiFeO 3 have been investigated. BiFeO 3 films with 15 at% Bi excess allow the control of lattice mismatch‐induced biaxial stress up to 10.8 GPa on SrTiO 3 (001) substrates. Heteroepitaxy of such films follows the Stranski–Krastanov growth mode, as suggested by island formation on the wetting layer accompanied with stress relaxation. The bandgap is linearly decreased with the in‐plane compressive stress, and a large stress coefficient of 67 meV/GPa was extracted. A 0.7 eV red‐shift of the bandgap was observed in the fully epitaxially strained film. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)