Unleashing the potential of 2D cold metals for emerging nanoelectronics: From NDR tunnel diodes to FETs

Two-dimensional (2D) cold metals, known for their extraordinary electronic characteristics, are poised to revolutionize nanoelectronics. This study leverages density functional theory and nonequilibrium Green's function methods to investigate the potential of 2D cold metals in lateral and vertical heterojunction tunnel diodes and field-effect transistors (FETs). By carefully selecting 2D cold metal electrodes, we achieve both Λ-type and N-type negative differential resistance (NDR) in tunnel diodes. The lateral AlI₂/MgI₂/AlI₂ diode displays an unprecedented Λ-type NDR with a peak-to-valley current ratio (PVCR) of 10¹², while vertical NbS₂/h-BN/NbS₂ and lateral NbSi₂N₄/HfSi₂N₄/NbSi₂N₄ diodes exhibit N-type NDR with moderate PVCRs of 10² to 10⁴ at room temperature [1,2]. Furthermore, FETs utilizing magnetic 2D cold metal source and drain electrodes demonstrate sub-60 mV/dec subthreshold swings, along with NDR and non-local giant magnetoresistance [3]. This combination of energy-efficient transistor behavior, non-volatile memory potential, and NDR effect opens new pathways for designing logic-in-memory architectures.

[1] E. Sasioglu and I. Mertig, ACS Applied Nano Materials 6, 3758-3766 (2023).

[2] P. Bodewei, E. Sasioglu, N.F. Hinsche, and I. Mertig, Phys. Rev. Applied 22, 014004 (2024).

[3] E. Sasioglu, P. Bodewei, N.F. Hinsche, and I. Mertig (unpublished).