Berlin 2024 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 40: 2D Materials and Heterostructures: Magnetic Properties
HL 40.4: Talk
Thursday, March 21, 2024, 10:15–10:30, EW 201
Computational design of two-dimensional cold metal lateral heterojunction (Nb/Hf)Si2N4 tunnel diodes — •Paul Bodewei, Ersoy Sasioglu, Nicki Frank Hinsche, and Ingrid Mertig — Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle (Saale), Germany
Cold metals have recently gained attention as a promising platform for innovative devices, such as tunnel diodes with negative differential resistance (NDR) [1] and field-effect transistors with subthreshold swings below the thermionic limit. Recently discovered two-dimensional (2D) transition metal carbides and nitrides have both metallic and semiconducting properties, making them ideal for these applications. We present a computational study of a prototype NbSi2N4/HfSi2N4/NbSi2N4 lateral heterojunction tunnel diode. Using density functional theory and a nonequilibrium Green function method, we investigate the current-voltage characteristics of these diodes with varying barrier thicknesses in zigzag and armchair orientations. Our results indicate negative differential resistance that leads to unconventionally high peak-to-valley current ratio (PVCR). Moreover, significant differences in peak current densities as well as PVCR for both armchair- and zigzag-orientations of the tunnel diodes have been found. These findings suggest that cold metal based materials hold promise for high PVCR NDR tunnel diodes, with potential applications in memory, logic circuits, and electronic devices. [1] Ersoy Şaşioğlu and Ingrid Mertig, ACS Appl. Nano Mater. 6, 3758-3766 (2023).
Keywords: tunnel diodes; negative differential resistance; 2D materials; quantum transport