Van der Waals contact between 2D magnetic VSe_(2)and transition metals and demonstration of high-performance spin-field-effect transistors  

二维磁性VSe_(2)与过渡金属的范德华接触及其高性能自旋场效应晶体管研究

作　　者：Jiaduo Zhu Xing Chen Wei Shang Jing Ning Dong Wang Jincheng Zhang Yue Hao 朱家铎;陈兴;尚蔚;宁静;王东;张进成;郝跃(Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory,School of Microelectronics,Xidian University,Xi’an 710071,China;Xidian-Wuhu Research Institute,Wuhu 241002,China;Shaanxi Joint Laboratory of Graphene,Xidian University,Xi’an 710071,China)

机构地区：[1]Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory,School of Microelectronics,Xidian University,Xi’an 710071,China [2]Xidian-Wuhu Research Institute,Wuhu 241002,China [3]Shaanxi Joint Laboratory of Graphene,Xidian University,Xi’an 710071,China

出　　处：《Science China Materials》2021年第11期2786-2794,共9页中国科学（材料科学（英文版）

基　　金：the 111 project(B12026);the National Natural Science Foundation of China(61904142);the Natural Science Basic Research Plan in Shaanxi Province of China(2019ZDLGY16-03)。

摘　　要：This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.本文利用密度泛函理论和量子输运方法研究了过渡金属(TM):Fe、Co、Ni/2H-VSe_(2)杂化纳米结构的界面耦合和自旋输运特性.由于TM-Se-V的间接耦合作用导致体系的磁矩明显减小且2H-VSe_(2)半金属特性消失,所以预期的独立过渡金属、VSe_(2)的自旋过滤效果在接触区域变差.尽管如此,所有基于TM/2H-VSe_(2)的双端口器件仍呈现出一种有趣的偏压依赖自旋注入效率(SIE),其中Co/2H-VSe_(2)获得了非常可观的自旋输出电流:高达666 mA mm^(-1).进一步提出的基于过渡金属/2H-VSe_(2)的自旋场效应晶体管表现出出色的性能.在基于Ni/2H-VSe_(2)的晶体管中实现了非常高的自旋极化电流,高达3117 mA mm^(-1),器件同时还具有106 mV dec-1的开关特性.更为重要的是,所有晶体管在栅压的调控下,实现了自旋抽取效率(SEE)从96%到-92%连续可调,这些结果表明该器件有望应用于高性能自旋电子器件.

关 键 词：VSe2 CONTACT DFT spin-FET 

分 类 号：TN386[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]