title: Electrically Tunable Bandgaps in Bilayer MoS₂.
abstract: Artificial semiconductors with manufactured band structures have opened up many new applications in the field of optoelectronics. The emerging two-dimensional (2D) semiconductor materials, transition metal dichalcogenides (TMDs), cover a large range of bandgaps and have shown potential in high performance device applications. Interestingly, the ultrathin body and anisotropic material properties of the layered TMDs allow a wide range modification of their band structures by electric field, which is obviously desirable for many nanoelectronic and nanophotonic applications. Here, we demonstrate a continuous bandgap tuning in bilayer MoS2 using a dual-gated field-effect transistor (FET) and photoluminescence (PL) spectroscopy. Density functional theory (DFT) is employed to calculate the field dependent band structures, attributing the widely tunable bandgap to an interlayer direct bandgap transition. This unique electric field controlled spontaneous bandgap modulation approaching the limit of semiconductor-to-metal transition can open up a new field of not yet existing applications.
authors.affiliation: School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.|Globalfoundries Advanced Technology, Hopewell Junction, New York 12533, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Chu
authors.affiliation: School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Hesameddin
authors.initials: H
authors.lastname: Ilatikhameneh
authors.affiliation: School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klimeck
authors.affiliation: School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Rajib
authors.initials: R
authors.lastname: Rahman
authors.affiliation: School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Chen
keywords: bilayer MoS2; dual gate FET; interlayer transition; photoluminescence; transition metal dichalcogenides (TMD); tunable bandgap