Emission properties of YAG: Ce ceramics with barium fluoride flux

In this work, we investigated the luminescent properties of YAG, Ce ceramics with an addition of barium fluoride flux. The ceramic samples were sintered from obtained YAG: Ce, BaF2 phosphor powder. Morphological, luminescent and decay time characteristics of YAG: Ce ceramics were investigated. The luminescence decay kinetics analysis of the ceramics showed that the decay time in phosphors and ceramics is different in the visual spectral range

Nanocomposition of PEDOT:PSS with metal phthalocyanines as promising hole transport layers for organic photovoltaics

PEDOT:PSS is one of the most widely used materials as a hole selective layer in organic photovoltaics due to its easy processing and high reproducibility. Unfortunately, the material is limited when testing new donor:acceptor systems due to its intrinsic frontier energy levels which typically leads to energy losses due to inadequate energy level alignment and presence of resistive losses. In this work, PEDOT:PSS:metal phthalocyanines nanocomposite thin films are formulated and used as hole transport layer for organic solar cells (OSCs). PEDOT:PSS is formulated with H2Pc, CuPc, CoPc and ZnPc metal phthalocyanines (MPc) with nanobelt morphology which confers the compatibility with the active layer. Atomic force microscopy (AFM) and x-ray diffraction (XRD) were used to study the morphology and structure of nanocomposite films, respectively. OSCs based on PEDOT:PSS:MPc nanocomposite films were fabricated and the effect of hybrid hole transport layer with various phthalocyanines on photovoltaics properties was studied. Overall, nanocomposition of PEDOT:PSS with metal phthalocyanines improves the final power conversion efficiency of solar cells by 20% by a reduction of the resistive losses due to inadequate energy level alignment. The addition of metal phthalocyanines to PEDOT:PSS is a promising method for tailor-made hole transport materials for new donor:acceptor systems to improve their efficiencies.Funding for open access charge: CRUE-Universitat Jaume

The effect of BaF2 concentration and particle size distribution on the luminescence efficiency of YAG:Ce3+phosphors

Y3Al5O12 (YAG) phosphor powders doped with Ce3+ concentration were synthesized by the solid-state reaction method with different of BaF2 flux concentration. Morphological characterization, photoluminescent properties and decay characteristics of YAG phosphor powders were studied. It was shown that BaF2 directly influenced on particle size distribution of YAG:Ce3+ phosphor. It is necessary to have both large particles agglomerates (size more than 40 μm) and small one (size less than 4 μm) to obtain high energy efficiency in polydisperse YAG:Ce3+ phosphors. It was evidenced, that the effect of both large and small agglomerates on energy efficiency is observed. The luminescence decay time for all investigated samples is significantly different in the spectral range 500 and 700 nm from τ ~ 60 to 80 ns, respectively

Density and microstructural investigation of Ce:YAG ceramic subjected to powerful ultrasonic treatment during the compaction process

The aim of the present work was to investigate the effect of the applied pressure, sintering temperature and ultrasonic treatment during the pressing process on the density and microstructure of translucent ceramics based on yttrium-aluminum garnet doped with cerium ions (Ce: YAG) obtained by conventional sintering of pressed compacts. The optimization of manufacturing conditions of the ceramics was carried out. It was shown that the ultrasonic treatment of initial powder in optimal sintering conditions leads to an increase in the relative density and grain size and decrease in the pore size of the sintered ceramics

Emission properties of YAG: Ce ceramics with barium fluoride flux

In this work, we investigated the luminescent properties of YAG, Ce ceramics with an addition of barium fluoride flux. The ceramic samples were sintered from obtained YAG: Ce, BaF2 phosphor powder. Morphological, luminescent and decay time characteristics of YAG: Ce ceramics were investigated. The luminescence decay kinetics analysis of the ceramics showed that the decay time in phosphors and ceramics is different in the visual spectral range

Structural and Luminescent Peculiarities of Spark PlasmaSintered Transparent MgAl2O4 Spinel Ceramics Doped withCerium Ions

In the present study, the concentration series of MgAl2O4 :Ce3+ ceramics have been fabricated by the Spark Plasma Sintering (SPS) method. Cerium-doping concentration was varied within a range of 0.1–5 wt.%. The prepared ceramics have been tested using the various experimental techniques: X-ray diffraction (XRD), scanning electron microscopy, as well as optical and thodoluminescence spectroscopy. According to XRD, all synthesized samples are biphasic with structural impurities. The cerium ion concentration effect on the athodoluminescent characteristics of MgAl2O4:Ce3+ ceramics has been studied in terms of emission intensity and decay time. Before annealing the concentration, quenching is observed. The optimal doping Ce3+ concentration was determined to be 5 wt.% after temperature annealing at 1300 ?C. The successfully prepared spinel ceramics could be potentially applying for high-energy electrons detection

Manufacturing Optically Transparent Thick Zirconia Ceramics by Spark Plasma Sintering with the Use of Collector Pressing

The efficiency of using the collector pressing scheme in the Spark Plasma Sintering (SPS) process has been confirmed in improving the optical, physical, and mechanical properties of yttria-stabilized zirconia (YSZ) ceramics with an increased shape factor. An approach for developing a seal surface and determining the optimal method of increasing pressure and temperature during SPS on this surface was used to optimize the consolidation modes of the materials. It has been shown that transparent/translucent YSZ ceramics with an increased shape factor (14 mm in diameter and up to 5 mm in height, h/d = 0.36) can be successfully fabricated by the SPS technique combined with the collector pressing scheme. The optical properties and microhardness of ceramics obtained using the collector scheme are better to the optical properties of ceramics obtained using the conventional uniaxial pressing scheme

Spark plasma sintering of transparent YAG:Ce ceramics with LiF flux

Transparent yttrium aluminum garnet (YAG) ceramics doped with cerium ions (Ce3+) were successfully synthesized using the spark plasma sintering (SPS) process at a temperature of 1600 °C, isothermal exposure 10 minutes, pressure 100 MPa and a heating rate 10 °C/min from a mechanical mixture of powders of yttrium, aluminum, and cerium oxides. Transmittance in the visible range for 1 mm thick samples is above 40 %; in the near infrared is above the 60 %. Vickers hardness was 15±1.05 GPa. The optimal SPS conditions have been discussed and suggested in order to obtain a good combination of density and transmittance