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arXiv · 1509.00516

Strain-induced energy band gap opening in two-dimensional bilayered silicon film

Zhonghang Ji·Ruiping Zhou·Lok C. Lew Yan Voon·Yan Zhuang
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Abstract

This work presents a theoretical study of the structural and electronic properties of bilayered silicon films under in-plane biaxial strain/stress using density functional theory. Atomic structures of the two-dimensional silicon films are optimized by using both the local-density approximation and generalized gradient approximation. In the absence of strain/stress, five buckled hexagonal honeycomb structures of the bilayered silicon film have been obtained as local energy minima and their structural stability has been verified. These structures present a Dirac-cone shaped energy band diagram with zero energy band gaps. Applying tensile biaxial strain leads to a reduction of the buckling height. Atomically flat structures with zero bucking height have been observed when the AA-stacking structures are under a critical biaxial strain. Increase of the strain between 10.7% ~ 15.4% results in a band-gap opening with a maximum energy band gap opening of ~168.0 meV obtained when 14.3% strain is applied. Energy band diagram, electron transmission efficiency, and the charge transport property are calculated.

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Zhonghang Ji, Ruiping Zhou, Lok C. Lew Yan Voon, Yan Zhuang. 2015-09-01. Strain-induced energy band gap opening in two-dimensional bilayered silicon film. https://doi.org/10.1007/s11664-016-4682-3

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