Renormalization of Molecular Energy Levels in Single-Molecule Nanojunctions: An Ab-initio Approach

International Conference on Materials Science and Technology 2012

Parashar, Sweta^1 ; Srivastava, Pankaj^1 ; Pattanaik, Manisha^1

Nanomaterials Research Group, Computational Nanoscience and Technology Lab, ABV-Indian Institute of Information Technology and Management, Morena Link Road, Gwalior (MP)

474015, India^1

关键词: Ab initio approach;    Electrostatic environments;    First principle calculations;    Molecular energy levels;    Molecular systems;    Non equilibrium greens functions (NEGF);    Polycyclic aromatic hydrocarbons (PAHS);    Single-molecule transistor;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/73/1/012117/pdf
DOI  :  10.1088/1757-899X/73/1/012117

来源: IOP

【 摘 要 】

Using first-principle calculations based on Density Functional Theory (DFT) in conjunction with the Non-Equilibrium Greens Functions (NEGF) technique, we have studied the effect of electrostatic environment in molecular energy levels of single-molecule transistors. This approach is applied to three polycyclic aromatic hydrocarbons (PAHs) anthracene, tetracene and pentacene, for calculating charging energies of molecular systems weakly coupled to an electrostatic environment. The result shows renormalization of molecular energy levels in an electrostatic environment. Further, it is observed that on increasing the number of aromatic rings, the addition energy value decreases which increases the conductivity of the system. Subsequently charge stability diagram for PAHs has been obtained.