Single atom impurity in a Single Molecular Transistor

TL;DR

This paper investigates how impurity atoms affect the electrostatic properties of single molecular transistors using ab-initio calculations, revealing potential for impurity detection and control in nano-electronic devices.

Contribution

It introduces a method to identify impurity positions in SMTs via charge stability diagrams and electrostatic analysis, enabling impurity detection at room temperature.

Findings

Charge stability diagrams reveal impurity positions.

Electrostatic control is enhanced by double-gated geometry.

Devices operate effectively at room temperature.

Abstract

The influence of an impurity atom on the electrostatic behaviour of a Single Molecular Transistor (SMT) was investigated through Ab-initio calculations in a double-gated geometry. The charge stability diagram carries unique signature of the position of the impurity atom in such devices which together with the charging energy of the molecule could be utilised as an electronic fingerprint for the detection of such impurity states in a nano-electronic device. The two gated geometry allows additional control over the electrostatics as can be seen from the total energy surfaces (for a specific charge state) which is sensitive to the positions of the impurity. These devices which are operational at room temperature can provide significant advantages over the conventional Silicon based single dopant devices functional at low temperature. The present approach could be a very powerful tool for the detection and control of individual impurity atoms in a single molecular device and for applications in future molecular electronics.