Dipeptide Constituting Oppositely Charged Amino Acids as Molecular Rectifier

Abstract

In order to explore peptides for future electronics applications, we have elucidated two different dipeptides consisting of positively charged and negatively charged amino acids namely Histidine-Aspartic and Histidine-Glutamic using NEGF-DFT approach. These two different molecules are bridged within three distinct but symmetrical electrodes of Au, Ag and Cu thereby forming six molecular devices. The Au-His-Glu-Au and Au-His-Asp-Au molecular devices offer the highest rectification ratio of 13.53 and 8.38, respectively. Similarly, Ag-His-Glu-Ag and Au-His-Asp-Au molecular devices offer the most significant negative differential resistance regime with peak to valley current ratio of 1.66 and 1.34, respectively.