COMPARISON OF THE ELECTRONIC PROPERTIES OF GRAPHENE NANORIBBONS DOPED WITH LITHIUM AND BERYLLIUM RESPECTIVELY USING THE DENSITY FUNCTIONAL THEORY APPROACH

• Main Author: FIKA RAHMADANI UTAMI MARTOPRAWIRO (NIM: 10206031); Pembimbing :Prof. Dr. Eng. Khairurrijal
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/15694
• Institution: Institut Teknologi Bandung

The density functional theory (DFT) approach was employed to analyze the electronic properties of pure armchair graphene nanoribbons and unpure armchair graphene nanoribbons. The electronic properties of graphene nanoribbons differ by depending on the shape of the edge and the length of the ribbon. Generally, there are three different edges, the armchair-shaped edge, the zig-zag shaped edge and random-shaped edge, though this final project will focus on the armchair-shaped edge graphene nanoribbons (AGNR). Once the electronic properties of AGNR is found, a calculation on each width of AGNR doped by Beryllium and Lithium resepectively is calculated. After gaining the results from the calculations, it is found that the most stable position of dopant differs for each different width and different dopant, and while Beryllium bonds with the Van-der-Walls bond, Lithium is more stronger, with a polarized covalent bond. <br /> <br /> <br /> <br /> <br /> By comparing the electronic properties of the pure graphene nanoribbons and the graphene nanoribbons that are doped, there has been found a few differrences. This includes their band gap, band stucture and DOS. From this comparison, it is discovered that though Beryllium does give effect to the AGNR, it is less than Lithium. On the AGNR with the width of 7 Carbon atoms or more, it is revealed that Lithium changes it to a conductor. <br /> <br /> <br /> <br /> <br /> Besides that, a comparison between the DFT method and the hybrid functional, B3LYP is also made. The package used for this final project is the Gaussian03 package for the B3LYP hybrid functional and the Siesta package for the density functional theory.