TY - JOUR
T1 - MoS2/MX2 heterobilayers
T2 - Bandgap engineering via tensile strain or external electrical field
AU - Lu, Ning
AU - Guo, Hongyan
AU - Li, Lei
AU - Dai, Jun
AU - Wang, Lu
AU - Mei, Wai Ning
AU - Wu, Xiaojun
AU - Zeng, Xiao Cheng
PY - 2014/3/7
Y1 - 2014/3/7
N2 - We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX2/MoS2 (M = Mo, Cr, W, Fe, V; X = S, Se). For M = Mo, Cr, W; X = S, Se, all heterobilayers show semiconducting characteristics with an indirect bandgap with the exception of the WSe 2/MoS2 heterobilayer which retains the direct-bandgap character of the constituent monolayer. For M = Fe, V; X = S, Se, the MX 2/MoS2 heterobilayers exhibit metallic characters. Particular attention of this study has been focused on engineering the bandgap of the TMD heterobilayer materials via application of either a tensile strain or an external electric field. We find that with increasing either the biaxial or uniaxial tensile strain, the MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can undergo a semiconductor-to-metal transition. For the WSe2/MoS2 heterobilayer, a direct-to-indirect bandgap transition may occur beyond a critical biaxial or uniaxial strain. For M (=Fe, V) and X (=S, Se), the magnetic moments of both metal and chalcogen atoms are enhanced when the MX2/MoS2 heterobilayers are under a biaxial tensile strain. Moreover, the bandgap of MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can be reduced by the vertical electric field. For two heterobilayers MSe2/MoS2 (M = Mo, Cr), PBE calculations suggest that the indirect-to-direct bandgap transition may occur under an external electric field. The transition is attributed to the enhanced spontaneous polarization. The tunable bandgaps in general and possible indirect-direct bandgap transitions due to tensile strain or external electric field make the TMD heterobilayer materials a viable candidate for optoelectronic applications.
AB - We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX2/MoS2 (M = Mo, Cr, W, Fe, V; X = S, Se). For M = Mo, Cr, W; X = S, Se, all heterobilayers show semiconducting characteristics with an indirect bandgap with the exception of the WSe 2/MoS2 heterobilayer which retains the direct-bandgap character of the constituent monolayer. For M = Fe, V; X = S, Se, the MX 2/MoS2 heterobilayers exhibit metallic characters. Particular attention of this study has been focused on engineering the bandgap of the TMD heterobilayer materials via application of either a tensile strain or an external electric field. We find that with increasing either the biaxial or uniaxial tensile strain, the MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can undergo a semiconductor-to-metal transition. For the WSe2/MoS2 heterobilayer, a direct-to-indirect bandgap transition may occur beyond a critical biaxial or uniaxial strain. For M (=Fe, V) and X (=S, Se), the magnetic moments of both metal and chalcogen atoms are enhanced when the MX2/MoS2 heterobilayers are under a biaxial tensile strain. Moreover, the bandgap of MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can be reduced by the vertical electric field. For two heterobilayers MSe2/MoS2 (M = Mo, Cr), PBE calculations suggest that the indirect-to-direct bandgap transition may occur under an external electric field. The transition is attributed to the enhanced spontaneous polarization. The tunable bandgaps in general and possible indirect-direct bandgap transitions due to tensile strain or external electric field make the TMD heterobilayer materials a viable candidate for optoelectronic applications.
UR - http://www.scopus.com/inward/record.url?scp=84894648640&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84894648640&partnerID=8YFLogxK
U2 - 10.1039/c3nr06072a
DO - 10.1039/c3nr06072a
M3 - Article
C2 - 24473269
AN - SCOPUS:84894648640
SN - 2040-3364
VL - 6
SP - 2879
EP - 2886
JO - Nanoscale
JF - Nanoscale
IS - 5
ER -