First principles study on geometric and electronic properties of two-dimensional Nb_(2)CT_(x) MXenes  

作　　者：Guoliang Xu Jing Wang Xilin Zhang Zongxian Yang 徐国亮;王晶;张喜林;杨宗献(Henan Key Laboratory of Photovoltaic Materials, School of Physics, Henan Normal University,Xinxiang 453000,China)

机构地区：[1]Henan Key Laboratory of Photovoltaic Materials, School of Physics, Henan Normal University,Xinxiang 453000,China

出　　处：《Chinese Physics B》2022年第3期504-510,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. U1804130, U2004212, 11904084, and 11874141);the Henan Overseas Expertise Introduction Center for Discipline Innovation (Grant No. CXJD2019005);the China Postdoctoral Science Foundation (Grant No. 2021M690933);the Key Scientific Research Projects of Henan Education Department, China (Grant No. 22A140020)。

摘　　要：MXenes are a new type of two-dimensional carbides with rich physical and chemical properties. The physics of MXenes, and thus the applications, are dominated by surface functional groups. Herein, the effects of different terminations(O,S, Se, Te) on the geometric and electronic properties of Nb_(2)C MXenes were studied via density functional theory(DFT)calculations. Three adsorption sites were examined to determine the most stable configurations. The results showed that both the types and the positions of surface functional groups influence the geometric stability and physical characters of Nb_(2)C. The S and Se terminations make the Nb_(2)C MXenes to be semiconductor, while Nb_(2)C MXenes with other terminations(O, Te) are conductor. The electron location function, density of states, Bader charge distribution, and the projected crystal orbital Hamilton population were conducted to explain the origin of adsorption stability and electronic nature difference. Our results provide a fundamental understanding about the effects of surface terminations on the intrinsic stability and electronic properties of Nb_(2)C MXenes.

关 键 词：Nb_(2)C MXenes surface functional groups geometric structure electronic properties 

分 类 号：O469[理学—凝聚态物理]