Ultrafast charge transfer between MoTe2 and MoS2 monolayers. (12th December 2016)

• Record Type: Journal Article
• Authors: Pan, Shudi; Ceballos, Frank; Bellus, Matthew Z; Zereshki, Peymon; Zhao, Hui
• Is Part Of: 2D materials. Volume 4:Number 1(2017)
• Publication Date: 2016-12-12
• Subjects: van der Waals interface -- transition metal dicholcogenide -- molybdenum ditelluride -- charge transfer -- transient absorption; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/4/1/015033
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: High quality and stable electrical contact between metal and two-dimensional materials, such as transition metal dichalcogenides, is a necessary requirement that has yet to be achieved in order to successfully exploit the advantages that these materials offer to electronics and optoelectronics. MoTe2, owing to its phase changing property, can potentially offer a solution. A recent study demonstrated that metallic phase of MoTe2 connects its semiconducting phase with very low resistance. To utilize this property to connect other two-dimensional materials, it is important to achieve efficient charge transfer between MoTe2 and other semiconducting materials. Using MoS2 as an example, we report ultrafast and efficient charge transfer between MoTe2 and MoS2 monolayers. In the transient absorption measurements, an ultrashort pump pulse is used to selectively excite electrons in MoTe2 . The appearance of the excited electrons in the conduction band of MoS2 is monitored by using a probe pulse that is tuned to the resonance of MoS2 . We found that electrons transfer to MoS2 on a time scale of at most 0.3 ps. The transferred electrons give rise to a large transient absorption signal at both A-exciton and B-exciton resonances due to the screening effect. We also observed ultrafast transfer of holes from MoS2 to MoTe2 . Our results suggest the feasibility of using MoTe2 as a bridge material to connect MoS2 and other transition metal dichalcogenides, and demonstrate a new transition metal dichalcogenide heterostructure involving MoTe2, which extends the spectral range of such structures to infrared.