L-Glutamic acid (i.e. L-amino acid) based molecular junction as rectifiers

Abstract

Dissimilar metal electrodes in molecular junction play significant role in exploring the intriguing properties of biomolecules. One such property is rectification ratio, which ensures the candidature of different biomolecules as nanoelectronics devices. Protein based nanoelectronics devices are gaining enduring attention among researchers working in the field of bio nanotechnology. The alluring properties of proteins can be predicted if the subunit i.e. amino acids be explored individually. With the aim of exploring amino acid based nanoelectronics devices, we consider the negatively charged amino acid (i.e., L-Glutamic acid, (C5H9NO4)) with dissimilar metal electrodes on either side, forming Au-Glutamic-Ag, Au-Glutamic-Cu and Ag-Glutamic-Cu molecular junctions. The first-principle calculations are performed using Density functional theory in local density approximations (DFT-LDA). The molecule with dissimilar electrodes offers dissimilar rectification ratio and finite negative differential resistance. The Au-Glutamic-Cu molecular device exhibits highest while Ag-Glutamic-Cu exhibits the lowest zero bias conductance values. Higher rectification ratio and lower Homo-Lumo gap is observed with Au-Glutamic-Cu and Au-Glutamic-Ag molecular devices. Such investigation highlights the prospect of L-Glutamic acid like biomolecules for future nanoelectronic devices.