Two-dimensional MoTe2/SnSe2 van der Waals heterostructures for tunnel-FET applications

Journal article, 2022

Two-dimensional (2D) van der Waals heterostructures (vdWHs) are attractive candidates for realizing tunnel field-effect transistors (TFETs) for low-power applications. In this work, using first-principles calculations based on density functional theory (DFT), we explore heterostructures composed of 2D MoTe2 and SnSe2. Our calculations reveal that upon forming the heterostructures, the valence band top of MoTe2 and the conduction band bottom of SnSe2 are almost aligned, forming the nearly broken-gap or type-III band alignment which is highly promising for TFETs. Interestingly, we find that the band alignment can be tuned by applying external electric fields. For positive electric fields, MoTe2 (SnSe2) band-edge positions are shifted upward (downward) with respect to the Fermi level, and more electrons are expected to tunnel from MoTe2 to SnSe2. Overall, our simulations provide fundamental insights into the electronic properties of MoTe2/SnSe2 stacks, and pave the way for the design and fabrication of future MoTe2/SnSe2-based TFETs.