Electronic, optoelectronic, and thermoelectric properties of single molecular devices of 2D fullerenes with zigzag graphene nanoribbons as electrodes

Abstract

Zigzag graphene nanoribbons (GNRs) were selected as electrodes, and the electron transport properties, optical properties, and thermoelectric properties of four fullerene cluster-based molecular devices were studied. By applying different voltages on them, their I–V curves exhibited the multiple negative differential resistance (NDR) effect and the platform effect, which are described in more detail using their density of states (DOS) and projected density of states (PDOS). The results of rotating two types of (C₆₀)₄ molecules verify that both the NDR and the platform effects are essential characteristics of them. Furthermore, an examination is conducted on the photocurrent of the devices at the point of maximum light absorption, revealing that α-(C₆₀)₄ connected by a [2+2] ring addition bond in the transport direction exhibits superior optical properties and works better as a photoelectric device than β-(C₆₀)₄ connected via a C–C single bond in the transport direction. Finally, the thermoelectric current of the devices was studied. Our results contribute to the understanding and the potential application of single devices based on fullerene clusters in the area of molecular electronics.