Analytical Modeling of Current and Quantum Capacitance of Single-Electron Transistor with Island Made of Armchair WSe2 Nanoribbon

Abstract

Single-electron transistors (SETs), which operate by quantum-mechanically controlled coulomb blockade and the single-electron tunneling effect, are promising candidate future nanoelectronic devices. A physics-based analytical model is developed to study the current and quantum capacitance of a SET with an island made of monolayer tungsten diselenide (WSe2) nanoribbon in an armchair pattern. It is noteworthy that the SET current is not degraded much in the coulomb blockade region, whereas outside this region, the SET current decreases with varying width of the nanoribbon, presumably due to the greater width of the potential well in the island that lowers the tunneling rate. Since atomically thin nanoribbon possesses quantum capacitance, which might cause further degradation in the SET performance, its influences are also studied. A three-band nearest-neighbor tight-binding model is applied to assimilate the details and information of the energy band formation into the quantum capacitance estimation.