Electrical transport and rectification in a typical heterostructure based on fullerene–pentacene suspended to copper leads

Abstract

In this work, we study quantum electrical transport through a heterojunction molecular bridge based on a fullerene and a pentacene as an electron-poor and electron-rich, respectively, coupled to two copper semi-infinite electrodes. Our calculations are based on the Green’s function approach within the nearest-neighbor tight-binding approximation. For this reason, a theoretical generalized derivation is introduced to calculate the self-energy of a centered-cubic lattice electrode using a unitary transformation. Based on this model, the effects of different geometrical ways of contacts and also various values of the applied gate voltage are examined, comprehensively. The estimations obviously clarify that the value of the transmission coefficient of carriers for single contact is significantly different from multiple contacts, particularly near to the Fermi level. The model predicts that tunable rectification can be achieved via gate voltage and also different ways of coupling of the C $$_{60}$$ to the electrode. The reification ratio value of the device with six contacts of the C $$_{60}$$ molecule to the left electrode approaches over than 1400, when the gate voltage of 2.0 V is applied. The results can be applied in electronic devices and logic circuits based on molecular diodes.