相关论文: Intrinsically slow cooling of hot electrons in CdS…
We report a first-principles description of inelastic lifetimes of excited electrons in real Cu and Al, which we compute, within the GW approximation of many-body theory, from the knowledge of the self-energy of the excited quasiparticle.…
A theory of electron spin relaxation in semiconducting carbon nanotubes is developed based on the hyperfine interaction with disordered nuclei spins I=1/2 of $^{13}$C isotopes. It is shown that strong radial confinement of electrons…
Fulfilling the potential of the colloidal semiconductor quantum dots (QDs) in electrically driven applications remains a challenge largely since operation of such devices involves charged QDs with drastically different photo-physical…
Semiconductor nanowires (NWs) have shown evidence of robust hot carrier effects due to their small dimensions. The relaxation dynamics of hot carriers in these nanostructures, generated by photo-absorption, are of great importance in…
We report the synthesis and optical characterization of fully inorganic gradientshell CdSe/CdZnS nanocrystals (NCs) with high luminescence quantum yield (QY, 50 percent), which were obtained by replacing native oleic-acid (OA) ligands with…
We compute the transient dynamics of phonons in contact with high energy "hot" charge carriers in 12 polar and non-polar semiconductors, using a first-principles Boltzmann transport framework. For most materials, we find that the decay in…
Hot carriers are energetic photo-excited carriers driving a large range of chemico-physical mechanisms. At the nanoscale, an efficient generation of these carriers is facilitated by illuminating plasmonic antennas. However, the ultrafast…
Structural and charge relaxation of nanoclusters of CdSe of diameter 1-2 nm are studied with first principle calculations. The relaxations cause significant distortions of smaller systems of ~ 1 nm in diameter and have very minimal effect…
We present a real-time investigation of ultrafast carrier dynamics in single-wall carbon nanotube bundles using femtosecond time-resolved photoelectron spectroscopy. The experiments allow to study the processes governing the subpicosecond…
The blinking dynamics of colloidal core-shell CdSe/CdS dot-in-rods is studied in detail at the single particle level. Analyzing the autocorrelation function of the fluorescence intensity, we demonstrate that these nanoemitters are…
The rates of elementary photophysical processes in nanocrystals, such as carrier cooling, multiexciton generation, Auger recombination etc., are determined by monitoring the transient occupation of the lowest exciton band. The underlying…
Electron-hole pairs in semiconductors are essential for solar cells and fast electronic circuitry, but the competition between carrier transport and relaxation into heat limits the efficiency and speed. Here we use ultrafast electron…
We have studied the dynamics of electrons in single wall carbon nanotubes using femtosecond time-resolved photoemission. The lifetime of electrons excited to the pi* bands is found to decrease continuously from 130 fs at 0.2 eV down to less…
We investigate charge relaxation rates due to acoustic phonons in weakly-confined quantum dot systems, including both deformation potential and piezoelectric field interactions. Single-electron excited states lifetimes are calculated for…
Atomically thin films of Pb on Si(111) provide an experimentally tunable system comprising a highly structured electronic density of states. The lifetime of excited electrons in these states is limited by both electron-electron (e-e) and…
We study nanoelectromechanical resonators fabricated from suspended flakes of NbSe$_2$ (thickness$\sim$30-50 nm) to probe charge density wave (CDW) physics at nanoscale. Variation of elastic and electronic properties accompanying the CDW…
Molybdenum carbide (MoC) is a promising candidate for substituting expensive platinum-group metals in many applications owing to its low cost and excellent properties. A comprehensive understanding of the carrier dynamics in MoC facilitates…
For high-speed optoelectronic applications relying on fast relaxation or energy transfer mechanisms, understanding of carrier relaxation and recombination dynamics is critical. Here, we compare the differences in photoexcited carrier…
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…
Electron-electron scattering is one of the most important hot carrier relaxation pathways in plasmonic nanoparticles. Understanding the dynamics of this scattering process and the effects of this on excited state dephasing and relaxation is…