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Quantum dots have excellent optical properties such as broad excitation spectra, tunable emission spectra, large Stokes shift, quantum-enhanced luminescence efficiency and so on. In this work, CuInS2 quantum dots were prepared successfully by utilizing the non-thermal injection method. They had diameters in the range of 2∼4 nm. The average diameter of the dots was about 2.4 nm. The dominant wavelength...
In this work, transparent oxyfluoride glass-ceramics obtained by the adequate heat treatment of Nd3+-doped glass with composition SiO2-Al2O3-Na2O-LaF3 are investigated. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM) show that the precipitated nanocrystals are LaF3 with a crystal size between 9 – 12 nm. Site-selective and time-resolved emission and excitation...
This paper presents the development of a novel luminescence-based trace oxygen sensor that will eventually lead to the production of a commercial sensor for use in gaseous sensing applications. The proprietary sensing formulation provides the means of a robust and stable sensor using a metalloporphyrin complex as the luminescent indicator that is efficiently quenched by oxygen. The spectroscopic properties...
Concept, equipment, and exploitation of spatio-time-resolved cathodoluminescence (STRCL) spectroscopy will be presented. As one of its advantages is unlimited bandgap energy of the sample, we show STRCL data of high AlN mole fraction AlxGa1−xN structures. For understanding the mechanisms of the improvement in the luminescence efficiency of Al0.68Ga0.32N / Al0.77Ga0.23N multiple quantum wells by proper...
The optimum pair of bands in the fine structure of nanoparticles luminescence spectra used for measuring local temperature of biological tissue had been determined.
Application of crystalline materials in ionizing radiation detectors has played a crucial role in the discovery of properties of matter. Future detector concepts at HEP experiments will require a tolerable level of radiation damage in particular caused by energetic hadrons: minor deterioration of the optical transmission, low level of afterglow and radio-luminescence. From systematic studies of the...
Cryo-cathodoluminescence was used to investigate defects present in Cu2ZnSnS4 thin films. Four luminescence peaks of energies P1: 0.90 eV, P2: 1.04 eV, P3: 1.18 eV, and P4: 1.29 eV were investigated in detail and a fifth peak at ∼1.6 eV was also noted. Based on a power-series analysis, P1, P2, and P3 are attributed to free-to-bound or donor-acceptor-pair transitions while P4 appears excitonic in nature...
The avalanche behavior of 650V and 1200V SiC Merged-PN-Schottky diodes was investigated as function of temperature by means of electrical measurements, simulation and optical detection of the avalanche rated electroluminescence. A very good fit between the simulated and experimentally determined breakdown field strengths could be achieved. The TC of the avalanche was 0.14V/K resp. 0.35V/K for the...
We demonstrate time- and space-resolved luminescence measurements of quantum degenerate paraexcitons in cuprous oxide. We report dynamics of ultracold excitons such as the drift in a trap potential, cooling process, and lifetime of exctions.
We report an investigation on pure and doped PbFCl crystals. Optical and scintillation properties, such as emission and transmittance spectra, light output and decay kinetics, were measured at different temperatures. Three emission bands at 2.27, 2.85 and 3.39 eV are observed at 77 K. Thermal quenching effect is also observed. While a scintillation component peaked at 400 nm with 3 ns decay time is...
Scintillation properties of a new cerium doped Rb2LiGdBr6 (RLGC) single crystal belongs to the elpasolite family is reported. This material is grown by the vertical Bridgman technique with 1% and 5% Ce3+-concentration (mole %). Under X-ray excitation, two overlapped emission peaks followed by broad band is observed between 350 to 680 nm wavelengths for 1% Ce sample. At 662 keV γ-rays RLGB: 5% Ce3+...
We have successfully grown pure and Pr3+-doped NaGd(WO4)2 (NGW) single crystals using the Czochralski pulling method. By employing a suitable rotation and pulling rates, good quality crystals of pure and Pr3+-doped NGW have been grown from the solution melt. Structural analyses of the grown samples are studied by X-ray diffraction (XRD). The x-ray induced emission spectrum shows a broad emission band...
Electron irradiation experiments were conducted to investigate the electron transport, charging, discharging, cathodoluminescence and emission properties of high-conductivity carbon-loaded polyimide (Black Kapton™). We discuss how these results are related to the nanoscale structure of the composite material. Measurements were conducted in an ultrahigh vacuum electron emission test chamber from <40...
Additional quenching of Er, Yb, Nd, and Bi luminescence in hydrogen impregnated silica optical fibers is revealed. Phenomenon is explained by deactivation of activators' excited states via collisions with hydrogen molecules migrating inside the glass network.
We present an approach to measure in situ the local temperature increase in the exposed volume during three-dimensional direct laser writing. The method is based on the detection of the luminescence of NaYF4:Yb3+/Er3+ codoped nanocrystals.
The photoluminescence (PL) properties of crystalline Er-Si-O compound on silicon substrate prepared using a simple method through evaporation and thermal annealing have been investigated. Diffraction peaks corresponding to crystalline Er-Si-O were clearly detected in X-ray diffraction measurements. Er-related infrared luminescence was observed at around 1.52 μm at room temperature. This luminescence...
Optical coatings of disordered thin film SiO2/SiOx dielectric samples on reflective metal substrates exhibited cathodoluminescence under electron beam irradiation. Measurements of the absolute radiance and emission spectra as functions of incident electron energy, flux and power over a range of sample temperatures are reported. Radiance reached a saturation plateau at high incident electron power...
The investigations of radio-luminescence (RL) in magnesium aluminates spinel crystals at variation of the time, intensity of X-irradiation and temperature of sample were provided. There were registered three prominent RL bands related to electron-hole recombination process at anti-site defects, emission of Mn2+-ions and emission of Cr3+-ions. The kinetics of the growth of indicated RL emissions show...
The ZnO thin films have been produced on p-type Si by the dip-coating method and after deposition were heated at different temperatures in the range from 650K to 850K. The photoluminescence (PL) and cathodoluminescence (CL) measurements were carried out at temperature range 12K-350K. I-V, C-V, Q-DLTS measurements were performed on the Al/ZnO/Si/Al structures at different temperatures. The electrical...
The multi-band luminescence and the excitation spectra, and the spectral reflectance of the undoped V2O5 in nano- and bulk-crystalline form at room temperature in the spectral range 200–900 nm were investigated. The nature of luminescence (peaked about 650 nm) is discussed with account of reflectance spectra and Electron Paramagnetic Resonance (EPR) investigations.
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