Thomas Heine and coworkers computationally designed a logical junction made from a single material, PdS2. Uniquely, 2D transition metal dichalcogenide PdS2 is semiconducting as a monolayer (ML) while it is semimetallic as a bilayer (BL). By exploiting this electronic phase transition, a ML junction can be made between BL contacts from a single material, minimizing resistance.
In this study, band structures have been calculated with self-consistent spin-orbit coupling in BAND and coherent transport calculations were performed with DFTB in conjunction with the non-equilibrium Green’s function (NEGF) approach. A proposed PdS2 junction behaves as a diode with a channel length of about 2.5 nm.
With field of 2D materials just emerging, novel device concepts in 2D electronics are waiting to be uncovered by explored properties of different combinations, potentially yielding unprecedented nanoelectronic properties.
Diode made from only 2D semi-conductor PdS2. Band structures of ML & BL (top left), I-V characteristics (top right), charge density (bottom left) and logical junction design (bottom right).
M. Ghorbani-Asl, A. Kuc, P. Miró, and T. Heine, A Single-Material Logical Junction Based on 2D Crystal PdS2, Adv. Mater. 28, 853-856 (2016)Key concepts2D semiconductors Charge Transport DFTB materials science nanoscience NEGF periodic DFT Relativistic DFT