Alignment of absorption resonances of single-walled carbon nanotubes and graphene nanoribbons

• Main Author: Payod, Renebeth B.
• Format: text
• Language: English
• Published: Animo Repository 2020
• Subjects: Carbon nanotubes; Absorption; Density functionals; Physics
• Online Access: https://animorepository.dlsu.edu.ph/etd_doctoral/1410; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=2461&context=etd_doctoral
• Institution: De La Salle University

The unique optical properties of low dimensional carbon nanostructures, such as graphene nanoribbons and single-walled carbon nanotubes, have attracted enormous attention in the scientific community due to the recent advancement to their atomical synthesis and optical characterization. Despite the fast development and a vast number of scientific publications, absorption resonance analysis describing a wide variety of graphene nanoribbons is still lacking due to the many different variations of ribbon edges. This study presents a systematic comparative statistical analysis of absorption resonance analysis between symmetric graphene nanoribbons and single-walled carbon nanotubes for a reliable prediction, design, and engineering of carbon-based optoelectronic devices. In particular, the tight-binding method and ab initio density functional theory that incorporated the exchange and correlation effects were used to acquire the energy dispersions and absorption resonances of these nanostructures. Statistical techniques are modified to determine quantitatively the relationship between optical absorption resonances of graphene nanoribbons and single-walled carbon nanotubes, specifically the linear correlation and alignment coefficients that are originally reformulated for this study. Our results show that the alignment of the absorption resonance for a tube-ribbon pair occurs when the number of carbon atoms in a nanotube unit cell is 2N + 4, where N is the number of carbon atoms in the nanoribbon unit cell. Thus, a novel atlas of zigzag graphene nanoribbons absorption resonances can be linearly mapped from an atlas of armchair single-walled carbon nanotubes optical transitions based on the empirical interpolating formula given by Liu et. al. (2012). Index Terms—Graphene nanoribbons, Single-walled carbon nanotubes, Absorption resonance, Tight-binding method, Density Functional Theory, Quantum Espresso, Linear Correlation, Alignment Coefficient, Statistical analysis.