Details

Autor(en) / Beteiligte

• Li, Quan
• Xu, Liang
• Luo, Kai-Wu
• Li, Xiao-Fei
• Huang, Wei-Qing
• Wang, Ling-Ling
• Yu, Ya-Bin

Titel

Electric-field-induced widely tunable direct and indirect band gaps in hBN/MoS2 van der Waals heterostructuresElectronic supplementary information (ESI) available. See DOI: 10.1039/c7tc00562h

Erscheinungsjahr

2017-05

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• First-principles calculations demonstrate that widely tunable direct and indirect band gaps can both be obtained in hBN/MoS 2 vertical heterostructures, under a finite vertical electric field ( E -field). In hBN/MoS 2 bi- and multi-heterostructures, the interactions between the two individuals produce a very special γ-band. Then, an enhancing forward E -field shifts this γ-band down and makes its lowest point become the conduction band minimum (CBM) of the hBN/MoS 2 bilayer at 0.47 V Å −1 , leading to a continuously tunable direct band gap. In contrast, an enhancing backward E -field shifts the valence band maximum (VBM) of the hBN up and makes it become the VBM of the hBN/MoS 2 bilayer at −0.07 V Å −1 , resulting in a highly tunable indirect band gap. Moreover, the magnitude of the two critical E -fields is obviously reduced when increasing the layer number of hBN flakes, offering multiple choices to devise band-gap tunable MoS 2 -based devices under only a weak E -field, which may be a significant breakthrough in MoS 2 -based field-effect transistors and photodetectors. Discovery of a special γ-band (an interfacial state) opens new opportunities to tune the band gaps of hBN/MoS 2 vdW heterostructures.