The effects of surface passivation on the photoluminescence (PL) properties of CdS nanoparticles oxidized by straightforward H2O2 injection were examined. Compared to pristine cadmium sulfide nanocrystals (quantum efficiency ≅ 0.1%), the surface-passivated CdS nanoparticles showed significantly enhanced luminescence properties (quantum efficiency ≅ 20%). The surface passivation by H2O2 injectio...

We present simultaneous near-field photoluminescence (PL) and Raman imaging of single-walled carbon nanotubes (SWNTs) with a spatial resolution better than 15 nm. Highly localized excitation is used to visualize the spatial extent of the contributing excited states. For SWNTs on glass, we typically observe highly confined PL from short segments of about 20 nm in length. The PL from micelle-enca...

This paper presents the characterization and analysis of a 16.8%-efficient 18 um silicon solar cell on steel substrate. Photoluminescence (PL) is used to monitor the solar cell’s fabrication step by step, and a correlation between PL intensity and implied open circuit voltage is established. PL images yield spatially resolved maps of key electrical parameters such as dark reverse saturation cur...

We report on the large photoluminescence redshift observed in nanostructures fabricated using n-type GaN by ultraviolet (UV) metal-assisted electroless chemical-etching method. The scanning electron microscopy (SEM) characterization showed nanostructures with size dispersion ranging from 10 to 100 nm. We observed the crystalline structure using high resolution transmission electron microscopy (...

We report on detailed temperature dependent, time-resolved photoluminescence (TRPL) studies of Si-doped AlGaN epilayers. In these samples, the Al concentration varies from 25% to 66%. The samples were found to exhibit metallic-like temperature-independent conductivity. The deep level "yellow" emission, whose presence would indicate the existence of a large number of defects associated with grow...

In this paper we present results of photoluminescence (PL), photoluminescence excitation (PLE), and time resolved PL spectroscopy of the I13/2 → I15/2 transition in Er optical centers in GaN epilayers grown by metal-organic chemical vapor deposition. Under resonance excitation via the higher-lying inner 4f shell transitions and band-to-band excitation of the semiconductor host, the PL and PLE s...

We report photoluminescence (PL) modulation of quantum dots (QDs) by photoinduced electron transfers from acridine-1,8-dione derivative surface ligands. Reversible PL switching upon many repeated cycles was demonstrated, as alternating on and off of the UV excitation for the surface ligand has successfully resulted in the QD PL modulation.

Photoluminescence (PL) identifies spectroscopic signatures of intertube transfer of optically pumped carriers in single-walled carbon nanotube (SWNT) ensembles. Resonant photoexcitation of large band gap SWNTs produces strong PL from smaller band gap SWNTs. Magnetic alignment measurements associate the energy-transfer PL peaks with the formation of SWNT bundles, suggesting that efficient coupli...

Core-shell structured silicon nanowires (Si NWs) were obtained by coating Si NWs with an HfO2 layer. Enhanced photoluminescence (PL) and a slightly decreased PL lifetime are achieved by HfO2 coating. Furthermore, the sensing stability is strongly improved. The improvement of PL properties is interpreted in terms of surface passivation and the Purcell effect.