Eur. Phys. J. B (2012) 85: 49
https://doi.org/10.1140/epjb/e2011-20442-1

Regular Article

From layers to nanotubes: Transition metal disulfides TMS₂

School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany

^a e-mail: a.kuc@jacobs-university.de

Received: 8 June 2011
Received in final form: 8 December 2011
Published online: 30 January 2012

Abstract

MoS₂ and WS₂ layered transition-metal dichalcogenides are indirect band gap semiconductors in their bulk forms. Thinned to a monolayer, they undergo a transition and become direct band gap materials. Layered structures of that kind can be folded to form nanotubes. We present here the electronic structure comparison between bulk, monolayered and tubular forms of transition metal disulfides using first-principle calculations. Our results show that armchair nanotubes remain indirect gap semiconductors, similar to the bulk system, while the zigzag nanotubes, like monolayers, are direct gap materials, what suggests interesting potential applications in optoelectronics.