Resonant enhancement of band-to-band tunneling in in-plane MoS₂/WS₂heterojunctions

Abstract

The band-to-band (BTB) tunneling current J through in-plane MoS 2 /WS 2 heterojunctions is calculated by the nonequilibrium Green function method combined with tight-binding approximation. Types A and B of band configurations are considered. For type-A (type-B) heterojunctions, a potential notch exists (or is absent) at the heterointerface. Both type-A and type-B MoS 2 /WS 2 heterojunctions can support a higher BTB current than MoS 2 and WS 2 homojunctions. For type-A heterojunctions, the resonant enhancement of J occurs resulting in a significantly higher BTB tunneling current.

Efficient and Chiral Electroluminescence from In‐Plane Heterostructure of Transition Metal Dichalcogenide Monolayers

“…[ 19,20 ] These features are promising for realizing their potential applications in functional light‐emitting devices [ 13,14 ] and low‐power consumption tunnel field effect transistors. [ 21,22 ]…”

“…[19,20] These features are promising for realizing their potential applications in functional light-emitting devices [13,14] and low-power consumption tunnel field effect transistors. [21,22] For such applications of in-plane hetero structures, one of the most important devices to invoke their electrical and optical functionalities is light-emitting diodes (LEDs), which provide an effective approach to control and visualize carrier recombination for probing excitonic optical responses. In particular, the interfaces of in-plane heterostructures have unusual band distributions/alignments originating from strain effects, offering peculiar light-emitting properties.…”

Analytical models for inter-layer tunneling in two-dimensional materials

“…However, in the case of inter-layer tunneling, the tunneling probability does not necessarily increase as the energy of the injected electron increases, because the velocity of the electron increases and the channel transit time decreases. Although the inter-layer tunneling can be analyzed in terms of quantum transport calculation, such as the Bardeen transfer Hamiltonian method [21][22][23][24] and the non-equilibrium Green function (NEGF) method, [25][26][27][28][29][30][31][32][33][34][35][36][37] it is of importance to develop a simple model of the inter-layer tunneling to understand the quantum transport results and to obtain a physical insight of the inter-layer tunneling.…”

Comparative simulation study of intra-layer band-to-band tunneling in monolayer transition metal dichalcogenides

“…Therefore, quantum mechanical effects must be properly incorporated to accurately simulate the properties of TFETs. The nonequilibrium Green function (NEGF) method 18,19) combined with the tight-binding (TB) approximation (TB-NEGF method) [20][21][22] is one of the most reliable and effective simulation methods to analyze quantum transport characteristics in such nano-scale devices, [23][24][25] including the full band-structure effects.…”

“…We have also investigated the intra-layer BTB tunneling through in-plane junctions of monolayer TMDs and found that heterojunctions can support a higher BTB tunneling current compared to homojunctions. 22) In the present study, we have performed a comparative study on the intra-layer BTB tunneling in in-plane homojunctions by using the TB-NEGF method. We especially focus on the differences in BTB tunneling transmission function according to structures (nanosheet and nanoribbon) or materials (MoS 2 , WS 2 , MoSe 2 , WSe 2 , MoTe 2 , and WTe 2 ).…”