Large Tunneling Magnetoresistance in van der Waals Ferromagnet/Semiconductor Heterojunctions. Issue 51 (13th October 2021)

• Record Type: Journal Article
• Authors: Zhu, Wenkai; Lin, Hailong; Yan, Faguang; Hu, Ce; Wang, Ziao; Zhao, Lixia; Deng, Yongcheng; Kudrynskyi, Zakhar R.; Zhou, Tong; Kovalyuk, Zakhar D.; Zheng, Yuanhui; Patanè, Amalia; Žutić, Igor; Li, Shushen; Zheng, Houzhi; Wang, Kaiyou
• Is Part Of: Advanced materials. Volume 33:Issue 51(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-13
• Subjects: pinholes -- tunneling magnetoresistance -- van der Waals magnetism; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202104658
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 2D layered chalcogenide semiconductors have been proposed as a promising class of materials for low‐dimensional electronic, optoelectronic, and spintronic devices. Here, all‐2D van der Waals vertical spin‐valve devices, that combine the 2D layered semiconductor InSe as a spacer with the 2D layered ferromagnetic metal Fe3 GeTe2 as spin injection and detection electrodes, are reported. Two distinct transport behaviors are observed: tunneling and metallic, which are assigned to the formation of a pinhole‐free tunnel barrier at the Fe3 GeTe2 /InSe interface and pinholes in the InSe spacer layer, respectively. For the tunneling device, a large magnetoresistance (MR) of 41% is obtained under an applied bias current of 0.1 µA at 10 K, which is about three times larger than that of the metallic device. Moreover, the tunneling device exhibits a lower operating bias current but a more sensitive bias current dependence than the metallic device. The MR and spin polarization of both the metallic and tunneling devices decrease with increasing temperature, which can be fitted well by Bloch's law. These findings reveal the critical role of pinholes in the MR of all‐2D van der Waals ferromagnet/semiconductor heterojunction devices. Abstract : A large tunneling magnetoresistance is observed in all van der Waals spin valves based on a Fe3 GeTe2 /InSe/Fe3 GeTe2 (ferromagnet/semiconductor/ferromagnet) heterojunction. Devices with the same thickness of the InSe layer reveal either a tunneling or a metallic transport behavior due to pinholes. This finding suggests opportunities for further development of this spin valve as a platform for nonvolatile memories and spin‐logic applications.