Exploring Electrostatic Confinement Transport in MoS2/WSe2 Heterostructure via Triple-Gated Point Contact Device

Abstract

The exponential development in quantum phenomena is directly correlated with the decreasing size of nano-semiconductor transistors. Consequently, the use of a quantum structure that deviates from traditional transistor types becomes imperative. Electrostatically defined nanoscale devices within 2D semiconductor heterostructures serve as foundational elements for diverse quantum electrical circuits. Van der Waals heterostructures, distinguished by atomically flat interfaces and inherent 2D characteristics, offer advantages such as large-scale uniformity, flexibility, and portability over conventional bulk semiconductor heterostructures. Herein, the intricate electronic behavior of a MoS2/WSe2 encapsulated heterostructure governed by split-gate and middle-gate configurations is investigated, revealing a distinctive step-like current profile at a low temperature of 77 K. The observed four regimes in the current highlight the impact of quantum confinement induced by reduced lateral dimensions, coupled with precise electrostatic confinement controlled by gate voltages. The temperature dependence of the phenomena emphasizes the role of thermal effects on carrier scattering mechanisms. In addition, the pinch-off characteristics with different temperatures, middle-gate voltages, and drain biases are explored. This study contributes to a deeper understanding of electrostatic effects in 2D transition metal dichalcogenide heterostructures and holds promise for the development of advanced electronic devices with tailored confinement for enhanced functionalities. © 2024 Wiley-VCH GmbH.