title: Triplet state absorption in carbon nanotubes: a TD-DFT study.
abstract: We predict properties of triplet excited states in single-walled carbon nanotubes (CNTs) using a time-dependent density-functional theory (TD-DFT). We show that the lowest triplet state energy in CNTs to be about 0.2-0.3 eV lower than the lowest singlet state energies. Like in pi-conjugated polymers, the lowest CNT triplets are spatially localized. These states show strong optical absorption at about 0.5-0.6 eV to the higher lying delocalized triplet states. These results demonstrate striking similarity of the electronic features between CNTs and pi-conjugated polymers and provide explicit guidelines for spectroscopic detection of CNT triplet states.
authors.affiliation: Theoretical Division, Center for Nonlinear Studies (CNLS), and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. serg@lanl.gov
authors.forename: Sergei
authors.initials: S
authors.lastname: Tretiak
mesh_terms: D000042:Absorption; D003198:Computer Simulation; D004579:Electron Transport; D008956:Models, Chemical; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry*; D017785:Photons
chemical_list: D037742:Nanotubes, Carbon