TY - JOUR
T1 - Two-Dimensional IV-V Monolayers with Highly Anisotropic Carrier Mobility and Electric Transport Properties
AU - Li, Pengfei
AU - Wu, Wenjun
AU - Xu, Yuehua
AU - Liu, Jun
AU - Wu, Shouliang
AU - Ye, Yixing
AU - Liang, Changhao
AU - Zeng, Xiao Cheng
N1 - Funding Information:
The C.L. group was financially supported by the National Natural Science Foundation of China (NSFC, 11604320, 51571186, 11674321, and 51801205) and the key research and development program of Anhui province (201904a05020049). Y.X. was financially supported by the National Natural Science Foundation of China (51772213). Calculations of transport properties were carried out in the High Performance Computing Laboratory of Changzhou University.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/1/28
Y1 - 2021/1/28
N2 - Two-dimensional (2D) semiconductors with anisotropic properties (e.g., mechanical, optical, and electric transport anisotropy) have long been sought in materials research, especially 2D semiconducting sheets with strong anisotropy in carrier mobility, e.g., n-type in one direction and p-type in another direction. Here, we report a comprehensive study of the carrier mobility and electric transport anisotropy of a class of 2D IV-V monolayers, XAs (X = Si or Ge), by using density functional theory methods coupled with deformation potential theory and non-equilibrium Green's function method. We find that the polarity of room-temperature carrier mobility μ of the 2D XAs monolayer is highly dependent on the lattice direction. In particular, for the SiAs monolayer, the μ values of the electron (e) and hole (h) are 1.25 × 103 and 0.39 × 103 cm2 V-1 s-1, respectively, in the a direction and 0.31 × 103 and 1.12 × 103 cm2 V-1 s-1, respectively, for the b direction. The computed electric transport properties also show that the SiAs monolayer exhibits strong anisotropy in the biased voltage in the range of -1 to 1 V. In particular, the current reflects the ON state in the a direction but the OFF state in the b direction. In addition, we find that the uniaxial strain can significantly improve the electric transport performance and even lead to the negative differential conductance at 10% strain. The unique transport properties of the 2D XAs monolayers can be exploited for potential applications in nanoelectronics.
AB - Two-dimensional (2D) semiconductors with anisotropic properties (e.g., mechanical, optical, and electric transport anisotropy) have long been sought in materials research, especially 2D semiconducting sheets with strong anisotropy in carrier mobility, e.g., n-type in one direction and p-type in another direction. Here, we report a comprehensive study of the carrier mobility and electric transport anisotropy of a class of 2D IV-V monolayers, XAs (X = Si or Ge), by using density functional theory methods coupled with deformation potential theory and non-equilibrium Green's function method. We find that the polarity of room-temperature carrier mobility μ of the 2D XAs monolayer is highly dependent on the lattice direction. In particular, for the SiAs monolayer, the μ values of the electron (e) and hole (h) are 1.25 × 103 and 0.39 × 103 cm2 V-1 s-1, respectively, in the a direction and 0.31 × 103 and 1.12 × 103 cm2 V-1 s-1, respectively, for the b direction. The computed electric transport properties also show that the SiAs monolayer exhibits strong anisotropy in the biased voltage in the range of -1 to 1 V. In particular, the current reflects the ON state in the a direction but the OFF state in the b direction. In addition, we find that the uniaxial strain can significantly improve the electric transport performance and even lead to the negative differential conductance at 10% strain. The unique transport properties of the 2D XAs monolayers can be exploited for potential applications in nanoelectronics.
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U2 - 10.1021/acs.jpclett.0c03656
DO - 10.1021/acs.jpclett.0c03656
M3 - Article
C2 - 33470821
AN - SCOPUS:85100187588
VL - 12
SP - 1058
EP - 1065
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 3
ER -