Oct 15 2014 Wednesday 15:30
Barbaros Özyılmaz, Graphene Research Center & Department of Physics, National University of Singapore
Graphene based transparent flexible condutors & Electronic charge and spin transport in grapheme-based heterostructures

Abstract: The unique electrical, optical mechanical and chemical properties of 2D crystals make them attractive from a technological standpoint. I will summarize the recent work has been done in 2D crystals by focuing particularly on charge and spin transport properties towards possible technological applications.

Graphene has attracted a lot of interest from a wide range of industries. Graphene's high mechanical strength & flexibility, optical transparency and exceptional heat & charge transport properties make it appealing for a wide range of novel device concepts. I will discuss two areas of research in my group. One of the main research directions in my group are polymers which can potentially boost tremendously the robustness of graphene films and simultaneously offer chemical resistance [1,2]. An example for such as polymer is PVDF. In addition, the multi-functionality of PVDF (ferro-electric, pyro-electric, piezo-electric) adds new possibilities for graphene's use in novel applications including nanogenerators, temperature sensors, etc. I will discuss recent results.

The second area of research is spintronics. For this purpose we have combined atomically thin layers of these materials in a layer-by-layer fashion and created a new three dimensional crystal with completely new properties. These new crystals are generally referred to as van der Waals heterostructures [3]. My group is in particular interested in enhancing graphene's spin transport properties by combining it with metal dichalcogenides such as tungsten disulfide. We have recently demonstrated that the spin orbit coupling of graphene can be enhanced by a factor of thousand, utilizing the proximity effect [4]. These efforts are the first steps towards spin-based electronics.

References:

[1] G,-X. Ni, B. Ozyilmaz et al., ACS Nano, 6(5),pp3935-3942 (2012).
[2] C. T. Toh, B. Ozyilmaz et al., to be submitted.
[3] A. K. Geim, I. V. Grigorieva, Nature, 499, 419-425 (2013).
[4] A. Avsar, B. Ozyilmaz et al., accepted for publication at Nature Communications (2014).