Transcript Slide 1

MoS2 nanoribbon transistor
Yanwen Liu, Xiang Yuan, Weiyi Wang, Cheng Zhang and Faxian Xiu*
Department of Physics and State Key Laboratory of Surface Physics
Fudan University, Shanghai, 200433, China
Introduction
2D mapping of differential conductance
Transition Matel dichalcogenides (TMDCs)
 Layer-by-layer structure
 Spin-orbit coupling
 Direct band gap in monolayer
 Excellent performance of FET
B=3T
B=0T
Wang, Q.H.at al Nature nanotechnology 7, 699-712 (2012).
Challenges in TMDCs
 Choose suitable metal to decrease
the Shottky barrier
 Mobility engineering
 PN junction
 Valley physics
B=9T
B=6T
Ioffe-Regel criterion
Motivation
 Constrict the width of nanoribbon for band gap engineering
The coulomb blockade diamonds split into more diamonds with magnetic
fields. As the magnetic field increases, diamonds increase.
Differential conductance with different magnetic field
 Study the ferromagnetic behavior of MoS2
 Study the quantum transport of MoS2 nanoribbon
Results
AFM image of the device
As magnetic field increases, the peaks of differential curve shift towards high
back gate voltage regime.
Differential conductance with different drain source voltage
The width of the device is 100nm. From the AFM image it can tell there is
some PMMA residue on the surface of the sample
IV curve and 2D mapping
Under small drain source voltage, the device has coulomb blockade behavior and
forms some quasi-plateaus. As the drain source voltage increases, the devices has
field effect transistor behavior.
Conclusion
IV curve of nanoribbon device at different back gate voltage. 2D mapping of
differential conductance shows some coulomb blockade diamond overlapped
each other.
● Scale down the MoS2 to the width of 100nm we get some quasi coulomb blockade
behavior;
● With magnetic field the coulomb blockade behavior is enhanced;
● However, the coulomb blockade behavior is still not significant enough, the coulomb
blockade oscillation is not observed, which means we should keep constricting the
width and take the measurement at lower temperature.
We gratefully acknowledge the financial support from the department.
*To whom correspondence should be addressed: [email protected]