Two-dimensional (2D) semiconductors have emerged as leading candidates for the development of low-power and multifunctional computing applications, thanks to their qualities such as layer-dependent band gap tunability, high carrier mobility, and excellent electrostatic control. Here, we explore a pair of 2D semiconductors with broken-gap (Type III) band alignment and demonstrate a highly gate-tunable p-MoTe2/n-SnS2 heterojunction tunnel field-effect transistor with multifunctional behavior. Employing a dual-gated asymmetric device geometry, we unveil its functionality as both a forward and backward rectifying device. Consequently, we observe a highly gate-tunable negative differential resistance (NDR), with a gate-coupling efficiency of η≃0.5 and a peak-to-valley ratio of ∼ 3 down to 150K. By employing density functional theory and exploring the density of states, we determine that interband tunneling within the valence bands is the cause of the observed NDR characteristics. The combination of band-to-band tunneling and gate controllability of NDR signal open the pathway for realizing gate-tunable 2D material-based neuromorphic and energy-efficient electronics.
@article{arxiv.2409.04908,
title = {Gate-tunable negative differential resistance in multifunctional van der Waals heterostructure},
author = {Richa Mitra and Konstantina Iordanidou and Naveen Shetty and Md Anamul Hoque and Anushree Datta and Alexei Kalaboukhov and Julia Wiktor and Sergey Kubatkin and Saroj Prasad Dash and Samuel Lara-Avila},
journal= {arXiv preprint arXiv:2409.04908},
year = {2024}
}