相关论文: Triplet excitations in carbon nanostructures
Atomistically detailed computational studies of nanocrystals, such as those derived from the promising lead-halide perovskites, are challenging due to the large number of atoms and lack of symmetries to exploit. Here, focusing on…
The effects of substrate on electronic and optical properties of triangular and hexagonal graphene nanoflakes with armchair edges are investigated by using a configuration interaction approach beyond double excitation scheme. The…
The effects of graphite surface geometrical deformation on the dynamics of conducting electrons are investigated theoretically. The analysis is performed within the framework of a deformation-induced gauge field and corresponding…
We use the robust nearest-neighbour tight-binding approximation to study on the same footing interband dipole transitions in narrow-bandgap carbon nanotubes and graphene nanoribbons. It is demonstrated that curvature effects in metallic…
The effects of Coulomb interactions on the electronic properties of bilayer graphene nanoribbons (BGNs) covered by a gate electrode are studied theoretically. The electron density distribution and the potential profile are calculated…
We investigate electric-field induced redshifts of photoluminescence from individual single-walled carbon nanotubes. The shifts scale quadratically with field, while measurements with different excitation powers and energies show that…
Armchair graphene nanoribbons are a highly promising class of semiconductors for all-carbon nanocircuitry. Here, we present a new perspective on their electronic structure from simple model Hamiltonians and $\textit{ab initio}$…
We present a quantitative theory of optical absorption polarized transverse to the tube axes in semiconducting single-walled carbon nanotubes. Transverse optical absorption in semiconducting single-walled carbon nanotubes is to an exciton…
The intrinsic near-infrared photoluminescence observed in long single walled carbon nanotubes is systematically quenched in ultrashort single-walled carbon nanotubes (usCNTs, below 100 nm length) due to their short dimension as compared to…
Carbon nanotubes are quantum sources whose emission can be tuned at telecommunication wavelengths by choosing the diameter appropriately. Most applications require the smallest possible linewidth. Therefore, the study of the underlying…
We demonstrate theoretically the feasibility of selective self-excitation of higher-mode flexural vibrations of graphene nano-ribbons and carbon nanotubes by the means of magnetomotive instability. Apart from the mechanical resonator, the…
Fifty years ago Walter Kohn speculated that a zero-gap semiconductor might be unstable against the spontaneous generation of excitons---electron-hole pairs bound together by Coulomb attraction. The reconstructed ground state would then open…
Graphene and carbon nanotubes represent the ultimate size limit of one and two-dimensional nanoelectromechanical resonators. Because of their reduced dimensionality, graphene and carbon nanotubes display unusual mechanical behavior; in…
The importance of finite-size effects for the electronic structure of long zigzag and armchair carbon nanotubes is studied. We analyze the electronic structure of capped (6,6), (8,0), and (9,0) single walled carbon nanotubes as a function…
The stability of trionic excitations in zigzag carbon nanotubes has been estimated. A trion is shown to be unstable with respect to the ground excitonic state and stable with respect to the excited one. So, trions in nanotubes of this type…
A theory of the long wavelength low energy electronic structure of graphite-derived nanotubules is presented. The propagating $\pi$ electrons are described by wrapping a massless two dimensional Dirac Hamiltonian onto a curved surface. The…
We show from many-body quantum mechanical calculations that there occur structurally distinct triplet-pair eigenstates in the intramolecular singlet fission (iSF) compound pentacene-tetracene-pentacene. Triplet excitons occupy neigboring…
Singlet exciton fission has the potential to increase the efficiency of crystalline silicon solar cells beyond the conventional single junction limit. Perhaps the largest obstacle to achieving this enhancement is uncertainty about energy…
We study strong coupling between plasmons in monolayer charge-doped graphene and excitons in a narrow gap semiconductor quantum well separated from graphene by a potential barrier. We show that the Coulomb interaction between excitons and…
We have studied emission properties of high-density excitons in single-walled carbon nanotubes through nonlinear photoluminescence excitation spectroscopy. As the excitation intensity was increased, all emission peaks arising from different…