相关论文: Molecular screening effects on exciton-carrier int…
We investigate adsorption effects of copper phthalocyanine molecules on excitons and trions in air-suspended carbon nanotubes. Using photoluminescence excitation spectroscopy, we observe that exciton energy redshifts gradually with the…
We observe trion emission from suspended carbon nanotubes where carriers are introduced electrostatically using field-effect transistor structures. The trion peak emerges below the $E_{11}$ emission energy at gate voltages that coincide…
We develop a scaling relationship between the exciton binding energy and the external dielectric function in carbon nanotubes. We show that the electron-electron and electron-hole interaction energies are strongly affected by screening yet…
Resonant Raman spectroscopy of single carbon nanotubes suspended across trenches displays red shifts of up to 30 meV of the electronic transition energies as a function of the surrounding dielectric environment. We develop a simple scaling…
Charge screening effect in metallic carbon nanotubes is investigated in a model including the one-dimensional long-range Coulomb interaction. It is pointed out that an external charge which is being fixed spatially is screened by internal…
We report the first observation of trions (charged excitons), three-particle bound states consisting of one electron and two holes, in hole-doped carbon nanotubes at room temperature. When p-type dopants are added to carbon nanotube…
We study the binding energies of singlet trions, i.e. charged excitons, in carbon nanotubes. The problem is modeled, through the effective-mass model, as a three-particle complex on the surface of a cylinder, which we investigate using both…
Exciton effects are studied in single-wall boron-nitride (BN) nanotubes. Linear absorption spectra are calculated with changing the chiral index of the zigzag nanotubes. We consider the extended Hubbard model with atomic energies at the…
Doping substantially influences the electronic and photophysical properties of semiconducting single-wall carbon nanotubes (s-SWNTs). Although prior studies have noted that surplus charge carriers modify optical spectra and accelerate…
The ground-state exciton binding energy for single-walled carbon nanotubes (SWCNTs) in vacuum calculated ignoring the screening of Coulomb interaction appears to be much greater than the corresponding band gap. The most essential…
One- and two-photon luminescence excitation spectroscopy showed a series of distinct excitonic states in single-walled carbon nanotubes. The energy splitting between one- and two-photon-active exciton states of different wavefunction…
Trion states of three correlated particles (e.g., two electrons and one hole) are essential to understand the optical spectra of doped or gated nanostructures, like carbon nanotubes or transition-metal dichalcogenides. We develop a…
Dielectric screening plays a vital role for the physical properties in the nanoscale and also alters our ability to detect and characterize nanomaterials by optical techniques. We study the dielectric screening inside of carbon nanotubes…
The interplay between discrete vibrational and electronic degrees of freedom directly influences the chemical and physical properties of molecular systems. This coupling is typically studied through optical methods such as fluorescence,…
The screening of Coulomb interaction controls many-body physics in carbon nanotubes, as it tunes the range and strength of the force that acts on charge carriers and binds electron-hole pairs into excitons. In doped tubes, the effective…
Electronic many-body correlation effects in one-dimensional (1D) systems such as carbon nanotubes have been predicted to modify strongly the nature of photoexcited states. Here we directly probe this effect using broadband elastic light…
Doping can profoundly affect the electronic- and optical-structure of semiconductors. Here we address the effect of surplus charges on non-radiative (NR) exciton and trion decay in doped semiconducting single-wall carbon nanotubes. The…
Carbon nanotubes (CNTs) are a one-dimensional material system with intriguing physical properties that lead to emerging applications. While CNTs are unusually strain resistant compared to bulk materials, their optical-absorption spectrum is…
We study the impact of a free carrier reservoir on the optical properties of excitonic and trionic complexes in a MoSe$_2$ monolayer at cryogenic temperatures. By applying photodoping via a non-resonant pump laser the electron density can…
Exciton effects are studied in single-wall boron-nitride nanotubes. The Coulomb interaction dependence of the band gap, the optical gap, and the binding energy of excitons are discussed. The optical gap of the (5,0) nanotube is about 6eV at…