Real time changes of the GaAs band structure were determined using time-resolved photoluminescence PL spectroscopy, with nanosecond resolution, in single-event continuous compression experiments. Continuous compression to 5 GPa over 150 ns was achieved by impacting fused silica buffers preceding the GaAs crystals. PL spectra and compression wave profiles were measured simultaneously for uniaxia...

Semiconductor nanocrystals emit light intermittently; i.e., they "blink," under steady illumination. The dark periods have been widely assumed to be due to photoluminescence (PL) quenching by an Auger-like process involving a single additional charge present in the nanocrystal. Our results challenge this long-standing assumption. Close examination of exciton PL intensity time traces of single C...

Low-temperature photoluminescence (PL) spectra of electron-hole systems in Si nanowires (NWs) prepared by thermal oxidization of Si fin structures were studied. Mapping of PL reveals that NWs with uniform width are formed over a large area. Annealing temperature dependence of PL peak intensities was maximized at 400 °C for each NW type, which are consistent with previous reports. Our results co...

Spatial distribution of photoluminescence (PL) spectra has been assessed in an InGaN single quantum well (SQW) structure by means of fluorescence microscopy and scanning near-field optical microscopy (SNOM) under illumination-collection mode. The PL intensity of fluorescence image is uniform at 77 K, but the dark spot areas were extended with increasing temperature. The nearfield PL images reve...

Visible and near-infrared photoluminescence (PL) at room temperature is reported from Si nanowires (NWs) grown by chemical vapor deposition from TiSi2 catalyst sites. NWs grown with average diameter of 20 nm were etched and oxidized to thin and passivate the wires. The PL emission blue shifted continuously with decreasing nanowire diameter. Slowed oxidation was observed for small nanowire diame...

Nanoposts of 10–40 nm top diameter on an InGaN/GaN quantum well structure were fabricated using electron-beam lithography and inductively coupled plasma reactive ion etching. Significant blue shifts up to 130 meV in the photoluminescence (PL) spectrum were observed. The blue-shift range increases with decreasing post diameter. For nanoposts with significant strain relaxation, the PL spectral pe...

A novel two-color photoluminescence (PL) is found in MnF(2) at room temperature under high pressure. Contrary to low-temperature PL, PL at room temperature is unusual in transition-metal concentrated materials like MnF(2), since the deexcitation process at room temperature is fully governed by energy transfer to nonradiative centers. We show that room-temperature PL in MnF(2) originates from tw...

We have fabricated Si nanoparticles from Si swarf using the beads milling method. The mode diameter of produced Si nanoparticles was between 4.8 and 5.2 nm. Si nanoparticles in hexane show photoluminescence (PL) spectra with peaks at 2.56, 2.73, 2.91, and 3.09 eV. The peaked PL spectra are attributed to the vibronic structure of adsorbed dimethylanthracene (DMA) impurity in hexane. The PL inten...

We investigate valley exciton dynamics in MoSe2 monolayers in polarizationand time-resolved photoluminescence (PL) spectroscopy at 4K. Following circularly polarized laser excitation, we record a low circular polarization degree of the PL of typically ≤ 5%. This is about 10 times lower than the polarization induced under comparable conditions in MoS2 and WSe2 monolayers. The evolution of the ex...

The optical properties of CdSe/Zn0.97Be0.03Se and CdSe/ZnSe quantum dots (QDs) are investigated using photoluminescence (PL) and PL excitation spectroscopies. We show that the addition of Be into the barrier enhances the Cd composition and the overall quantum confinement of optically active QDs. The temperature behavior of PL supports such a conclusion. We also show that the room temperature QD...