Biaxial stress-induced giant bandgap shift in BiFeO3 epitaxial films
Biaxial stress-induced giant bandgap shift in BiFeO3 epitaxial films
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BiFeO3 外延薄膜中双轴应力引起的巨大带隙位移
DOI：
10.1002/pssr.201105500
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发表时间：
2012-01-01
影响因子：
2.8
通讯作者：
Wu, J. L.
中科院分区：
文献类型：
--
作者：
Fu, Z.;Yin, Z. G.;Wu, J. L.
研究了厚度依赖性应力松弛及其对BiFeO3带隙的影响。在SrTiO3（001）衬底上，含有15% Bi过量的BiFeO3薄膜允许控制晶格错配引起的双轴应力高达10.8 GPa。这类薄膜的异质外延遵循stranski - krstanov生长模式，在润湿层上形成岛状并伴有应力松弛。带隙随面内压应力线性减小，提取出较大的应力系数为67 meV/GPa。在完全外延应变的薄膜中观察到0.7 eV的带隙红移。(C) 2011 WILEY-VCH Verlag GmbH & Co., KGaA, Weinheim
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. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim