Transport in vertically stacked hetero-structures from 2D materials

33rd International Conference on the Physics of Semiconductors

Chen, Fan^1 ; Ilatikhameneh, Hesameddin^1 ; Tan, Yaohua^1 ; Valencia, Daniel^1 ; Klimeck, Gerhard^1 ; Rahman, Rajib^1

Network for Computational Nanotechnology (NCN), Purdue University, West Lafayette

IN

47906, United States^1

关键词: Energy filtering;    Low power application;    Non-equilibrium Green's function;    Quantum transport simulations;    Switching mechanism;    Tight binding model;    Transition metal dichalcogenides;    Tunnel field-effect transistors (TFET);   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/864/1/012053/pdf
DOI  :  10.1088/1742-6596/864/1/012053

来源: IOP

【 摘 要 】

In this work, the transport of tunnel field-effect transistor (TFET) based on vertically stacked hereto-structures from 2D transition metal dichalcogenide (TMD) materials is investigated by atomistic quantum transport simulations. WTe2-MoS2 combination was chosen due to the formation of a broken gap hetero-junction which is desirable for TFETs. There are two assumptions behind the MoS2-WTe2 hetero-junction tight binding (TB) model: 1) lattice registry. 2) The S - Te parameters being the average of the S - S and Te - Te parameters of bilayer MoS2 and WTe2. The computed TB bandstructure of the hetero-junction agrees well with the bandstructure obtained from density functional theory (DFT) in the energy range of interest for transport. NEGF (Non-Equilibrium Green's Function) equations within the tight binding description is then utilized for device transfer characteristic calculation. Results show 1) energy filtering is the switching mechanism; 2) the length of the extension region is critical for device to turn off; 3) MoS2-WTe2 interlayer TFET can achieve a large on-current of 1000A/m with VDD= 0.3V, which suggests interlayer TFET can solve the low ON current problem of TFETs and can be a promising candidate for low power applications.