相关论文: Phonon and Electronic Non-radiative Decay of Excit…
Monoclinic bismuth vanadate (m-BiVO$_4$) is a promising indirect band gap semiconductor for photoelectrochemical water splitting, yet the characteristics of its low-lying photoexcitations, or excitons, remain poorly understood. Here, we use…
We calculate the electron-phonon scattering and binding in semiconducting carbon nanotubes, within a tight binding model. The mobility is derived using a multi-band Boltzmann treatment. At high fields, the dominant scattering is inter-band…
Exciton dynamics dictate the evolution of photoexcited carriers in photovoltaic and optoelectronic devices. However, interpreting their experimental signatures is a challenging theoretical problem due to the presence of both electron-phonon…
Simultaneous photoluminescence and photocurrent measurements on individual single-walled carbon nanotubes reveal spontaneous dissociation of excitons into free electron-hole pairs. Correlation of luminescence intensity and photocurrent…
Near-infrared magneto-optical spectroscopy of single-walled carbon nanotubes reveals two absorption peaks with an equal strength at high magnetic fields ($>$ 55 T). We show that the peak separation is determined by the Aharonov-Bohm phase…
In semiconductors, photoexcited electrons and holes (carriers) initially occupy high-energy states, but quickly lose energy to phonons and relax to the band edge within a picosecond [1]. Increasing the lifetime of carriers in…
We investigate the dynamics of the exciton formation and relaxation on a picosecond time scale following a pulsed photoexcitation of a semiconductor. The study is conducted in the framework of the density matrix theory complemented with the…
An analytical expression is obtained for the biexciton binding energy as a function of the inter-exciton distance and binding energy of constituent quasi-one-dimensional excitons in carbon nanotubes. This allows one to trace biexciton…
We have observed large-amplitude coherent phonon oscillations of radial breathing modes (RBMs) in single-walled carbon nanotubes excited through the lowest-energy (E11) interband transitions. In contrast to the previously-studied coherent…
The effect of phonons on a nonlinear optical response of a quantum dot-cavity system in quantum strong coupling regime can be accounted for by a fully analytical treatment, provided that the exciton-phonon dynamics is much faster than the…
We report first-principles calculations of the effects of quasiparticle self-energy and electron-hole interaction on the optical properties of single-walled BN nanotubes. Excitonic effects are shown to be even more important in BN nanotubes…
We propose a framework for inducing strong optomechanical effects in a suspended carbon nanotube based on deformation potential exciton-phonon coupling. The excitons are confined using an inhomogeneous axial electric field which generates…
The decay of the optical phonon into the two phonons of smaller energy is calculated for Si nanocrystals. The rate of the process is in the range of 1 to 10 ps. Such anharmonic phonon decay may control the energy relaxation rate of excited…
The properties of excitons in semiconducting single-walled carbon nanotubes (SWCNTs), isolated in vacuum or a medium, and their contributions to the optical spectra of nanotubes are studied within the elementary potential model, in which an…
Combining time-dependent density functional calculations for electrons with molecular dynamics simulations for ions, we investigate the dynamics of excited carriers in a (3,3) carbon nanotube at different temperatures. Following an hv=6.8…
We studied the nonlinear time-resolved luminescence signals due to multiexciton recombination processes in single-walled carbon nanotubes (SWNTs) using femtosecond excitation correlation (FEC) spectroscopy. From theoretical analysis of the…
We theoretically estimate the electron-phonon coupling constant lambda for metallic single-walled carbon nanotubes with a diameter of 1.4 nm. The partial electron-phonon coupling constant for the hardest phonon mode is estimated to be about…
Since the discovery of semiconducting monolayer transition metal dichalcogenides, a variety of experimental and theoretical studies have been carried out seeking to understand the intrinsic exciton population decay and valley relaxation…
Electron scattering rates in metallic single-walled carbon nanotubes are studied using an atomic force microscope as an electrical probe. From the scaling of the resistance of the same nanotube with length in the low and high bias regimes,…
We present evidence that the strong electron-electron interactions in gapped carbon nanotubes lead to finite hierarchies of excitons within a given nanotube subband. We study these hierarchies by employing a field theoretic reduction of the…