Morphology and photoluminescence (PL) properties for microcrystalline cellulose (MCC), microcrystalline nitrite powders of common formulae MNO2 (M=Na, K) (MCN) and two-component materials composed of both MCC and MCN have been prepared and characterized by means of optical microscopy and luminescence spectroscopy. This study aimed to clarify a possibility of low-limit determination of the nitri...

The spectroscopic behavior of colloidal InP quantum dots (QDs) has been investigated as a function of the mean QD diameter (which ranged from 26 to 60 Å). Absorption spectra show up to three peaks or shoulders which reflect excited state transitions in the QDs. Global photoluminescence (PL) spectra (excitation well to the blue of the absorption onset and which consequently excites most of the Q...

in this study un-doped and eu-doped zno nanorods and microrads were fabricated by chemical vapor deposition (cvd) method. the effects of annealing, synthesis temperature and structure on structural and photoluminescence properties of eu-doped zno samples were studied in detail. prepared samples were characterized using x-ray diffraction (xrd), scanning electron microscopy (sem), particle size a...

Carrier localization phenomena in indium-rich InGaN/GaN multiple quantum wells (MQWs) grown on sapphire and GaN substrates were investigated. Temperature-dependent photoluminescence (PL) spectroscopy, ultraviolet near-field scanning optical microscopy (NSOM), and confocal time-resolved PL (TRPL) spectroscopy were employed to verify the correlation between carrier localization and crystal qualit...

In this article, I will discuss the optical properties of SiO2-nanoparticles that we have investigated recently by photoluminescence (PL) spectroscopy. In particular, I will show the blue-shifts of PL, originating from the electron-hole recombination of the self-trapped exciton (STE), observed in smaller-sized SiO2-nanoparticles. To explain the size effect in relating to the STE PL shift, a que...

Time-resolved photoluminescence ~PL! spectra are reported for gas-suspended 1–10 nm diameter SiOx particles formed by laser ablation of Si into 1–10 Torr He and Ar. Three spectral bands ~1.8, 2.5 and 3.2 eV! similar to PL from oxidized porous silicon were measured, but with a pronounced vibronic structure. Particle size and composition were determined with Z-contrast transmission electron micro...

We report investigations of CdS–CdSe–CdS (core–well–shell) nanostructures by photoluminescence (PL) spectroscopy at temperatures between 77 and 300 K. PL intensity measurements show a transition from a pumprate-limited regime at low excitation intensity to the range determined by a spontaneous emission lifetime at a high excitation limit. PL intensity changes as a function of temperature. Also,...

In this paper, we report the synthesis of tin oxide (SnO2) nanoparticles by co-precipitation technique. The structural, surface morphology, thermal and optical properties of the SnO2 samples were analysed using X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM), Fourier transformed infrared (FTIR) spectrum, thermo gravimetric analysis (TGA/DT...

 Oxyfluoride glass ceramics containing CaF2nano-crystals doped with Y3+ ions were prepared by one-step crystallization of SiO2- Al2O3- CaO- CaF2 glasses at different temperatures. X- ray diffraction (XRD) results have revealed that CaF2 was the only precipitated crystalline phase in glass ceramic samples. According to the XRD results, a glass ceramic was selected as the best sample in order to ...

These glutathione (GSH)-conjugated CdTe/CdSe core/shell quantum dot (QD) nanoparticles in aqueous solution were synthesized using a microwave-assisted approach. The prepared type II core/shell QD nanoparticles were characterized by UV-Vis absorption, photoluminescence (PL) spectroscopy, X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). Results reveale...