Controllable Schottky Barriers between MoS2 and Permalloy

• Published in: Scientific reports 2014-11, Vol.4 (1), p.6928-6928, Article 6928
• Main Authors: Wang, Weiyi, Liu, Yanwen, Tang, Lei, Jin, Yibo, Zhao, Tongtong, Xiu, Faxian
• Format: Article
• Language: English
• Subjects: 140/133; 147/135; 639/766/1130/2798; 639/766/119/995; Electrodes; Humanities and Social Sciences; Injection; Low temperature; multidisciplinary; Science; Temperature; Temperature effects; Transistors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep06928

MoS 2 is a layered two-dimensional material with strong spin-orbit coupling and long spin lifetime, which is promising for electronic and spintronic applications. However, because of its large band gap and small electron affinity, a considerable Schottky barrier exists between MoS 2 and contact metal, hindering the further study of spin transport and spin injection in MoS 2 . Although substantial progress has been made in improving device performance, the existence of metal-semiconductor Schottky barrier has not yet been fully understood. Here, we investigate permalloy (Py) contacts to both multilayer and monolayer MoS 2 . Ohmic contact is developed between multilayer MoS 2 and Py electrodes with a negative Schottky barrier, which yields a high field-effect mobility exceeding 55 cm 2 V −1 s −1 at low temperature. Further, by applying back gate voltage and inserting different thickness of Al 2 O 3 layer between the metal and monolayer MoS 2 , we have achieved a good tunability of the Schottky barrier height (down to zero). These results are important in improving the performance of MoS 2 transistor devices; and it may pave the way to realize spin transport and spin injection in MoS 2 .