The natural lifetimes of a large number of the vibrational levels of the excited à 2Σ+ electronic state of the family of rare gas complexes, R·SH (R=Ne, Ar, and Kr) and their deuterides, are reported. It is well known that the natural lifetime of the à 2Σ+ state of isolated SH/D is markedly shortened by a photofragmentation process. Our results for the complexes show that the rare gas atom play...

We observed the optically forbidden energy transfer between cubic CuCl quantum dots coupled via an optical near-field interaction using time-resolved near-field photoluminescence (PL) spectroscopy. The energy transfer time and exciton lifetime were estimated from the rise and decay times of the PL pump-probe signal, respectively. We found that the exciton lifetime increased as the energy transf...

Chemical potential μeh and radiative lifetime τrad behaviour vs. carrier density n in FASnI3. They change dramatically with hole doping concentration, inducing large Burstein–Moss shift

A complex of salmon milt deoxyribonucleic acid (DNA) and the cationic surfactant cetyltrimethylammonium (CTMA) forms an organic-soluble biomaterial that can be readily incorporated within an organically modified silane-based xerogel. The photoluminescence (PL) intensity and excited-state luminescence lifetime of tris(4,7'-diphenyl-1,10'-phenanathroline) ruthenium(II) [(Ru(dpp)3](2+), a common O...

Time-resolved photoluminescence ~PL! spectroscopy has been used to study the radiative recombination of excitons bound to ionized donors in GaN doped with both Mg and Si at concentrations of 5310/cm and 1.5310/cm, respectively. Low temperature (T;10K) time-resolved, as well as integrated PL spectra, identify an ionized donor-bound ~Si! exciton peak (DX) approximately 11.5 meV below and a neutra...

A series of mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh3)X] (X = Cl, Br, I), based on 4-(3,5-diphenyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)pyrimidine (L) and triphenylphosphine, have been synthesized by reaction between CuX (X = Cl, Br, I), L and PPh3 in a molar ratio of 1/1/1 in MeCN solutions. The copper atom, showing the distorted tetrahedral environment, is bound by the N,N-...

The development of a space-based solar pumped laser system has been the focus of NASA research for several years. This laser would have application in power transmission to space vehicles and bases on the moon or Mars, where it could provide a means of electric power generation, propulsion, and communication[l]. An evaluation of prospective laser materials over the past decade has resulted in t...

We report a spectroscopic study of highly photostable individual CdSe/ZnS colloidal nanocrystals. At low temperature, photoluminescence spectra display two sharp zero-phonon lines which we attribute to the radiative recombination from the two lowest levels of the band-edge exciton fine structure. For the first time, resonant photoluminescence excitation spectra of these lines is performed, and ...

The structure and dynamics of luminescent excitons in tetracene thin films and nanoaggregates are investigated using time-resolved spectroscopy and theoretical calculations. The orientation of tetracene's transition dipole moment along its short molecular axis leads to properties qualitatively different from those observed in aggregates of phenylene-vinylene and thiophene oligomers, despite sim...

The temporal evolution of fluorescence from isolated single-wall carbon nanotubes (SWNTs) has been investigated using optical Kerr gating. The fluorescence emission is found to decay on a time scale of 10 ps. This fast relaxation arises from nonradiative processes, the existence of which explains the relatively low observed fluorescence efficiency in isolated SWNTs. From the measured decay rate...