Negative Differential Resistance Device with High Peak-to-Valley Ratio Realized by Subband Resonant Tunneling of Γ-Valley Carriers in WSe2/ h-BN/WSe2 Junctions

Kei Kinoshita; Rai Moriya; Seiya Kawasaki; Shota Okazaki; Momoko Onodera; Yijin Zhang; Kenji Watanabe; Takashi Taniguchi; Takao Sasagawa; Tomoki Machida

doi:10.1021/acsnano.4c09569

Negative Differential Resistance Device with High Peak-to-Valley Ratio Realized by Subband Resonant Tunneling of Γ-Valley Carriers in WSe₂/ h-BN/WSe₂ Junctions

ACS Nano. 2024 Oct 13. doi: 10.1021/acsnano.4c09569. Online ahead of print.

Authors

Affiliations

¹ Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro ,Tokyo153-8505, Japan.
² Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa 226-8501, Japan.
³ Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
⁴ International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
⁵ Research Center for Autonomous Systems Materialogy, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa 226-8501, Japan.

PMID: 39396194
DOI: 10.1021/acsnano.4c09569

Abstract

Resonant tunneling diodes (RTDs) are a core technology in III-V semiconductor devices. The realization of high-performance RTD using two-dimensional (2D) materials has been long awaited, but it has yet to be accomplished. To this end, we investigate a range of WSe₂/h-BN/WSe₂ RTD devices by varying the number of layers of source and drain WSe₂. The highest peak-to-valley ratio (PVR) is demonstrated in the three-layer (3L) WSe₂/h-BN/1-layer (1L) WSe₂ structure. The observed PVR values of 63.6 at 2 K and 16.2 at 300 K are the highest among the 2D material-based RTDs reported to date. Our results indicate the two key conditions to achieve high PVR: (1) resonant tunneling should occur between the Γ-point bands of the source and drain electrodes, and (2) the Γ-point bands contributing to the resonant tunneling should be energetically separated from the other bands. Our results provide an important step to outperform III-V semiconductor RTDs with 2D material-based RTDs.

Keywords: 2D materials; negative differential resistance; peak-to-valley ratio; resonant tunneling; subband; transition-metal dichalcogenides; van der Waals heterostructures.