Molecular Transistors with Perpendicular Gate Field Architecture: A Strong Gate Field Effect

Abstract

In this work we study the transport properties of molecular transistors with bridges based on 1,4-benzene-dithiol (BDT) and 2-nitro-1,4-benzene-dithiol (nitro-BDT) using ab initio electron propagator calculations that include electron correlations. In the proposed architecture of a transistor, the gate electric field is chosen to be perpendicular to the plane of a benzene ring. For the transistor with a BDT molecular bridge, strong negative differential resistance is found. This behavior does not exist in the traditional architecture where the gate field is parallel to the benzene ring plane. We find that the peak in the IV curves strongly depends on gate voltage. Our results show that the position of the peak shifts toward lower values of source-drain voltage with the gate voltage. A molecular transistor based on the nitro-BDT molecular bridge also reveals a strong negative differential resistance behavior. We find well-pronounced maxima and minima for both positive and negative values of source-drain vo...