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Layer dependent direct tunneling behaviors through two dimensional titania nanosheets
Pu, Yayun1,3,4; Xie, Xiong1,2; Wang, Liang2; Shen, Jun1
2020-02-15
摘要Two dimensional titania nanosheets are drawing increasing attention in academic and industrial community because of their versatile properties. The elucidation of the electron tunneling effect through their intrinsic metal-oxide-metal (MOM) atomic structures is imperative to further advance their applications as atomic dielectrics and memristors. The direct tunneling behaviors through Ti1-delta O24 delta- nanosheets sandwiched by two metal electrodes are studied by a modified WKB approximation and conformed by ab-initio calculation. Our results show that the tunneling current density depends exponentially on the stack number of dielectric Ti1-delta O24 delta- layers, decreases by 3-4 orders of magnitude for each layer addition, varying from 10(6) to 10(-8) A/cm(2) in one- to five-layer MOM structures. Also, it is highlighted that the localized intercalation charges naturally embedded in chemically-derived Ti1-delta O24 delta- nanosheets could reduce tunneling current by 3 orders of magnitude and that a thickness threshold of three layers (similar to 2 nm) exists as to the titania nanosheets not to exceed a gate current density of 1 A/cm(2) at 1 V. The present method could be extended to better clarify the electron tunneling behaviors in other two-dimensional gate dielectrics.
关键词Two dimensional oxides Titania nanosheet Electron tunneling WKB approximation
DOI10.1016/j.commatsci.2019.109398
发表期刊COMPUTATIONAL MATERIALS SCIENCE
ISSN0927-0256
卷号173页码:5
通讯作者Wang, Liang(wangliang@cigit.ac.cn) ; Shen, Jun(shenjun@cqu.edu.cn)
收录类别SCI
WOS记录号WOS:000506172700033
语种英语