Titanium Trisulfide Monolayer: Theoretical Prediction of a New Direct-Gap Semiconductor with High and Anisotropic Carrier Mobility

Authors

Jun Dai, University of Nebraska-LincolnFollow
Xiao Cheng Zeng, University of Nebraska-LincolnFollow

Date of this Version

6-2015

Citation

Published in Angewandte Chemie International Edition 54:26 (June 22, 2015), pp. 7572–7576; doi: 10.1002/anie.201502107 and Angewandte Chemie 127 (June 22, 2015), pp. 7682–7686; doi: 10.1002/ange.201502107

Comments

Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Used by permision.

Abstract

A new two-dimensional (2D) layered material, namely, titanium trisulfide (TiS₃) monolayer, is predicted to possess novel electronic properties. Ab initio calculations show that the perfect TiS₃ monolayer is a direct-gap semiconductor with a bandgap of 1.02 eV, close to that of bulk silicon, and with high carrier mobility. More remarkably, the in-plane electron mobility of the 2D TiS₃ is highly anisotropic, amounting to about 10,000 cm² V⁻¹ s⁻¹ in the b direction, which is higher than that of the MoS₂ monolayer, whereas the hole mobility is about two orders of magnitude lower. Furthermore, TiS₃ possesses lower cleavage energy than graphite, suggesting easy exfoliation for TiS₃. Both dynamical and thermal stability of the TiS₃ monolayer is examined by phonon-spectrum calculation and Born–Oppenheimer molecular dynamics simulation. The desired electronic properties render the TiS₃ monolayer a promising 2D atomic-layer material for applications in future nanoelectronics.

Includes Supplemental Materials (Fig. S1)