First Principles Study on Electronic and Optical Properties of Single Walled Carbon Nanotube for Photonics Application

Abstract

Recent research works on single-walled carbon nanotube (SWCNT) based material has witnessed a great technological importance in photonic applications due to their unique optical characteristics. Present work aims to employ theoretical first principles study to explore the electronic and optical properties of SWCNT in the form of armchair nanotube. The theoretical simulation is done by using density functional theory (DFT) as implemented in the CASTEP computer code. Similar to almost gapless nature of graphene, formation of Fermi level of a relaxed SWCNT structure is found to be at a value approaching zero. The calculated electronic band structure shows a direct band gap of 0.259 eV with Dirac cone form between conduction and valence band. The optical spectrum shows a variation of real and imaginary of dielectric function with inter-band transition taking place along with frequency of the incident light. The absorption spectrum exhibits a significant degree of anisotropic characteristic with almost transparent nature ranging from near infrared to ultraviolet energy range. These optical spectra show excellent nonlinear optical features which remark the suitability in optoelectronic applications.

Confining Nano-GeP in Nitrogenous Hollow Carbon Fibers toward Flexible and High-Performance Lithium-Ion Batteries

“…CNTs with 25 Å were selected to calculate the Li diffusion from outside to inside via CASTEP, the tolerances were 1 × 10 –6 eV/atom, and energy cutoff was 650 eV. Transition states (TSs) were exploited using the fully linear synchronous transition/quadratic synchronous transition method. − The obtained TS approximation was then used to perform QST maximization and conjugate gradient minimization in succession. Li 144 Ge 384 P 384 was constructed via Amorphous Cell and placed into 250 and 25 Å CNTs, Li 36 Ge 96 P 96 was constructed and placed into 10 Å CNTs, and Li 9 Ge 24 P 24 was constructed and placed into 5 Å CNTs, respectively.…”

Insights into the Need for Ab Initio Calculations to Accurately Predict the Optical Properties of Metallic Carbon Nanotubes Based on Experimental Confrontation

“…Regarding m-SWCNTs, the literature reports both theoretical studies and experimental works. Theoretical investigations encompass a range of approaches, including first-principles numerical calculations , as well as analytical methods. , Most of the ab initio studies focused on the optical properties of semiconducting SWCNTs to predict their band gaps. − While there is some work concerning m-SWCNTs, a crucial aspect, namely, the contribution of intraband transitions that accounts for the metallic behavior of m-SWCNTs, is often missing . Movlarooy computed the dielectric functions for two metallic chiralities, (8,8) and (15,0); however, the trend of variations in optical properties as a function of diameter was not provided, making it difficult to extrapolate their behavior for other chiralities.…”

“…Regarding m-SWCNTs, the literature reports both theoretical studies and experimental works. Theoretical investigations encompass a range of approaches, including first-principles numerical calculations 13,14 as well as analytical methods. 15,16 Most of the ab initio studies focused on the optical properties of semiconducting SWCNTs to predict their band gaps.…”

Engineering of Hydrogenated (6,0) Single-Walled Carbon Nanotube under Applied Uniaxial Stress: A DFT-1/2 and Molecular Dynamics Study

“…In recent decades, nanoscience and nanotechnology have been directed to the carbon nanostructures (graphene, diamond, nanotubes, and nanowires, etc.) due to their fascinating physical properties − as well as their potential application in nanoelectronics. − With the discovery of graphene, other allotropes of carbon were also discovered and carbon nanotubes (CNTs) was one of them which was first discovered in 1991 . One dimensional (1D) single-walled carbon nanotubes (SWCNTs) have become a focal point for many researchers with the hope of constructing nanomechanical sensors, nanoelectronics and optoelectronic devices. − Many researchers have conducted extensive experimental and theoretical research on it. − Structurally, like in graphene, C–C bonds are formed by sp 2 bonding in CNTs.…”