Predicted septuple-atomic-layer Janus MSiGeN4 (M = Mo and W) monolayers with Rashba spin splitting and high electron carrier mobilities

doi:10.1039/d0tc05649a

IMR OpenIR

	Predicted septuple-atomic-layer Janus MSiGeN4 (M = Mo and W) monolayers with Rashba spin splitting and high electron carrier mobilities
	Guo, San-Dong 1,2; Mu, Wen-Qi 1; Zhu, Yu-Tong 1; Han, Ru-Yue 1; Ren, Wen-Cai 3,4
通讯作者	Guo, San-Dong(sandongyuwang@163.com)
	2021-02-21
发表期刊	JOURNAL OF MATERIALS CHEMISTRY C
ISSN	2050-7526
卷号	9 期号:7 页码:2464-2473
摘要	Janus two-dimensional (2D) materials have attracted much attention as they possess unique properties caused by their out-of-plane asymmetry, and have been achieved in many 2D families. In this work, Janus monolayers are predicted for a new 2D MA(2)Z(4) family by means of first-principles calculations, of which MoSi2N4 and WSi2N4 have been synthesized experimentally (Science, 2020, 369, 670-674). The predicted MSiGeN4 (M = Mo and W) monolayers exhibit dynamical, thermodynamic and mechanical stability, and they are indirect band-gap semiconductors. The inclusion of spin-orbit coupling (SOC) gives rise to Rashba-type spin splitting, which is observed in the valence bands, which are different from the common conduction bands. The calculated results show valley polarization due to SOC, together with inversion symmetry breaking. It is found that MSiGeN4 (M = Mo and W) monolayers have much higher electron mobilities with respect to the hole mobilities. Both in-plane and much weaker out-of-plane piezoelectric polarizations can be observed when a uniaxial strain is applied in the basal plane. The values of the piezoelectric strain coefficient d(11) of the Janus MSiGeN4 (M = Mo and W) monolayers fall in between those of the MSi2N4 (M = Mo and W) and MGe2N4 (M = Mo and W) monolayers, as expected. It is proved that strain can tune the positions of the valence band maximum (VBM) and the conduction band minimum (CBM), and can enhance the strength of the conduction band convergence caused by compressive strain. It is also found that tensile biaxial strain can enhance the d(11) of the MSiGeN4 (M = Mo and W) monolayers, and the compressive strain can improve the d(31) (absolute values). Our predicted MSiGeN4 (M = Mo and W) monolayers, as derivatives of the 2D MA(2)Z(4) family, enrich the field of Janus 2D materials, and these results can motivate related experimental work.
资助者	Natural Science Foundation of Shaanxi Province Department of Education
DOI	10.1039/d0tc05649a
收录类别	SCI
语种	英语
资助项目	Natural Science Foundation of Shaanxi Province Department of Education[19JK0809]
WOS研究方向	Materials Science ; Physics
WOS类目	Materials Science, Multidisciplinary ; Physics, Applied
WOS记录号	WOS:000623516700025
出版者	ROYAL SOC CHEMISTRY
引用统计	被引频次：125[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/161559
专题	中国科学院金属研究所
通讯作者	Guo, San-Dong
作者单位	1.Xian Univ Posts & Telecommun, Sch Elect Engn, Xian 710121, Peoples R China 2.Xian Univ Posts & Telecommun, Key Lab Adv Semicond Devices & Mat, Xian 710121, Peoples R China 3.Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China 4.Univ Sci & Technol China, Sch Mat Sci & Engn, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Guo, San-Dong,Mu, Wen-Qi,Zhu, Yu-Tong,et al. Predicted septuple-atomic-layer Janus MSiGeN4 (M = Mo and W) monolayers with Rashba spin splitting and high electron carrier mobilities[J]. JOURNAL OF MATERIALS CHEMISTRY C,2021,9(7):2464-2473.
APA	Guo, San-Dong,Mu, Wen-Qi,Zhu, Yu-Tong,Han, Ru-Yue,&Ren, Wen-Cai.(2021).Predicted septuple-atomic-layer Janus MSiGeN4 (M = Mo and W) monolayers with Rashba spin splitting and high electron carrier mobilities.JOURNAL OF MATERIALS CHEMISTRY C,9(7),2464-2473.
MLA	Guo, San-Dong,et al."Predicted septuple-atomic-layer Janus MSiGeN4 (M = Mo and W) monolayers with Rashba spin splitting and high electron carrier mobilities".JOURNAL OF MATERIALS CHEMISTRY C 9.7(2021):2464-2473.