Aachen Graphene FLAGSHIP seminars

 

Tuesday, April 10, 2018, 12 to 1pm

Peter Bøggild of DTU Denmark gives a talk about "Graphene at the edge of perfection"

 

Friday, June 15, 2018, 1 to 2pm

Dr. Shu Nakaharai (NIMS & MANA) on the topic: "Polarity-Controllable Transistors on 2D Materials"

The lecture will take place in room S3 in building Otto-Blumenthal-Str. 2 (above the workshop) at Campus Melaten.

Abstract:
Two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs) have been expected for future channel materials due to their atomically-thin and smooth surfaces, which can lead to reducing the short channel effects in the aggressively scaled CMOS technology. On the other hand, there remain some challenging issues of carrier doping, control of carrier type and transistor polarity. In this talk, at first, we will discuss how we can overcome the issue of carrier type control in TMDC semiconductors. Here, it will be reviewed that MoTe2, in contrast to MoS2, exhibits only weak Fermi level pinning at the Schottky junctions, and it can behave as both n- and p-type transistors depending on the work function of the contact metals. Finally, it will be discussed that MoTe2 can be expected to be the ideal ambipolar channel in a unique concept of polarity-controllable transistors in which the transistor polarity (n/p) can be changed by electrostatic gating.
 

 

 

Wednesday, June 5, 2018, 12 to 1pm

Dr. Shu Nakaharai (NIMS & MANA) on the topic: "Polarity-Controllable Transistors on 2D Materials"

Abstract:
Two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs) have been expected for future channel materials due to their atomically-thin and smooth surfaces, which can lead to reducing the short channel effects in the aggressively scaled CMOS technology. On the other hand, there remain some challenging issues of carrier doping, control of carrier type and transistor polarity. In this talk, at first, we will discuss how we can overcome the issue of carrier type control in TMDC semiconductors. Here, it will be reviewed that MoTe2, in contrast to MoS2, exhibits only weak Fermi level pinning at the Schottky junctions, and it can behave as both n- and p-type transistors depending on the work function of the contact metals. Finally, it will be discussed that MoTe2 can be expected to be the ideal ambipolar channel in a unique concept of polarity-controllable transistors in which the transistor polarity (n/p) can be changed by electrostatic gating.