Electronic, mechanical and optical properties of ultra-thin compounds

Date: 17 February 2016

Venue: University of Antwerp - Campus Groenenborger - Room U.241 - Groeneborgerlaan 171 - 2020 Antwerpen

Time: 4:00 PM - 5:00 PM

Organization / co-organization: Condensed Matter Theory (CMT)

Short description: CMT seminar presented by Dr Engin Torun

Electronic, mechanical and optical properties of ultra-thin compounds

After the successful synthesis of graphene in 2004, the attention of material science and condensed matter physics has been widened towards new single layer structures such as transition-metal dichalcogenides (TMDs), alkalineearth-metal hydroxide and post-transition metal chalcogenides. These single layer compounds and their heterostructures are promising candidates for next generation of flexible nanoelectronic devices due to their wide range of remarkable properties.

In this talk, I will focus on unique physical properties of several members of mentioned classes of materials by using first-principle calculations. In the first part of the talk, I will present our density functional theory (DFT) calculations on monolayer FeCl2 and WTe2. In this part, I will discuss the electronic and magnetic properties of FeCl2 and anisotropic electronic and mechanical properties of WTe2.[1,2] In the second part of the talk, I will focus on tuning the magnetic anisotropy (MA) in single-layer crystal structures. In this part, I will explain the origin of MA, its importance and how it can be induced to a 2D material.[3] Then, in the final part, I will present the optical properties of GaS-Ca(OH)2 bilayer heterostructure. In this part, I will briefly explain how the dielectric function and the oscillator strength of the optical transitions are obtained using DFT. Then, I will discuss the geometric, electronic and optical properties of the isolated GaS and Ca(OH)2 monolayers as well as the GaSCa(OH)2 heterostructure.[4]


1. E. Torun, H. Sahin, S. K. Singh, F.M. Peeters, Stable half-metallic monolayers of FeCl2, App. Phys. Lett. 106, 192404 (2015).
2. E. Torun, H. Sahin, S. Cahangirov, A. Rubio, and F. M. Peeters, Anisotropic electronic, mechanical and optical properties of monolayer WTe2, J. of App. Phys. in press (2016). preprint.
3. E. Torun, H. Sahin, C. Bacaksiz, R.T. Senger, F.M. Peeters, Tuning the magnetic anisotropy in single-layer crystal structures, Phys. Rev. B 92, 104407 (2015).
4. E. Torun, H. Sahin, and F. M. Peeters, Optical properties of GaS-Ca(OH)2 bilayer heterostructure, Phys. Rev. B 93, 075111 (2016).

Engin Torun, CMT group UAntwerpen

Contact email: lucian.covaci@uantwerpen.be

Link: http://cmt.uantwerpen.be