The energy relaxation of electrons in γ-In2Se3nanorods was investigated by the excitation-dependent photoluminescence (PL). From the high-energy tail of PL, we determine the electron temperature (Te) of the hot electrons. TheTevariation can be explained by a model in which the longitudinal optical (LO)-phonon emission is the dominant energy relaxation process. The high-quality γ-In2Se3nanorods ...

We report the distance-dependent energy transfer from an InGaN quantum well to graphene oxide (GO) by time-resolved photoluminescence (PL). A pronounced shortening of the PL decay time in the InGaN quantum well was observed when interacting with GO. The nature of the energy-transfer process has been analyzed, and we find the energy-transfer efficiency depends on the 1/d² separation distance, wh...

We demonstrate that the gap states at the interface of Ca and a phenylene vinylene oligomer thin film are responsible for the dramatic quenching of its photoluminescence (PL). Upon oxidation of the Ca layer, the midgap states are removed, and the PL intensity recovers. From the cumulative Ca deposition and oxidation study, a 30 Å Ca oxide layer between the oligomer and the Ca metal prevents PL ...

The photoluminescence (PL) and PL excitation (PLE) spectra of the isolated Zn vacancy sVZnd in ZnSe are measured under hydrostatic pressure to 50 kbar at 7 K. The PL band shifts with pressure, roughly 30% faster than the band gap. Compression decreases the Stokes shift, reflecting a reduction in the C3y lattice relaxation around the V 2 Zn site. Defect-molecule calculations show that this arise...

We studied exciton structures and the Aharonov-Bohm effect in a single carbon nanotube using micro-photoluminescence (PL) spectroscopy under a magnetic field at low temperatures. A single sharp PL peak from the bright exciton state of a single carbon nanotube was observed under zero magnetic field, and the additional PL of dark exciton state appeared below the bright exciton peak under high mag...

Photoluminescence (PL) dynamics in single-walled carbon nanotubes (SWNTs) has been studied by the femtosecond excitation correlation method with a 150 fs time resolution. The SWNT samples were synthesized by different methods and suspended in gelatin films or D2O solutions. The PL dynamics of SWNTs depends on the local environment surrounding the SWNTs rather than the synthesis methods. The ver...

Here we report two types of defect-induced photoluminescence (PL) blinking behaviors observed in single epitaxial InGaAs quantum dots (QDs). In the first type of PL blinking, the "off" period is caused by the trapping of hot electrons from the higher-lying excited state (absorption state) to the defect site so that its PL rise lifetime is shorter than that of the "on" period. For the "off" peri...

A new SnO2/mesoporous silica composite was synthesized by a facile method, tin vapor reduction method , in which mesoporous silica SBA-15 was treated with tin vapor at temperature above 700 C under inert atmosphere. This material displays enhanced room-temperature photoluminescence (RT-PL) at increased treatment temperature. It is proved that RT-PL properties of this composite are closely relat...

Photo-oxidation of densely packed monolayer of CdSe quantum dots ~QDs! was studied by time-resolved photoluminescence ~PL! spectroscopy. Electrons yielded in QDs by the strong laser-pulse irradiation can assist the oxidation of CdSe QDs. Such rapid photo-oxidation does not introduce more nonradiative defects, instead, it enhances the coupling between QDs through surface modification and the PL ...

In indirect band gap GaAs1−xPx alloys, the Nx levels of the excitons bound to nitrogen have been resonantly excited. The detection of the photoluminescence (PL) at energies greater than the excitation energy (Anti-Stokes Luminescence (ASL)) shows a new PL band which appears at temperatures lower than 40 K. Its mean energy 2.205 eV is nearly independent of the alloy composition. We investigate A...