Biaxial stress‐induced giant bandgap shift in BiFeO3 epitaxial films |
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| Authors: | Z. Fu Z. G. Yin N. F. Chen X. W. Zhang H. Zhang Y. M. Bai J. L. Wu |
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| Affiliation: | 1. Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, P.R. China;2. School of Renewable Energy Engineering, North China Electric Power University, Beijing 102206, P.R. China |
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| Abstract: | Thickness‐dependent stress relaxation and its influence on the bandgap of BiFeO3 have been investigated. BiFeO3 films with 15 at% Bi excess allow the control of lattice mismatch‐induced biaxial stress up to 10.8 GPa on SrTiO3(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) |
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| Keywords: | bandgaps biaxial stress BiFeO3 lattice mismatch |
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