A novel blue light-emitting phosphor, Eu2+-doped magnesium strontium aluminate (MgSrAl10O17:Eu2+), for plasma display panel (PDP) application was developed. X-ray diffraction (XRD) patterns disclosed that the phosphor annealed at 1500 °C for 5 h was a pure MgSrAl10O17 phase. Field emission scanning electron microscopy (FE-SEM) images showed the particle size of the phosphor was less than 3 μm. The phosphor shows strong and broad blue emission under vacuum ultraviolet (VUV) light excitation. After baking at 400-600 °C and irradiation with VUV light for 300 h, the phosphor still keep excellent VUV luminescence properties exhibiting good stability against high temperature baking and VUV irradiation. The decay time was short as 1.09 μs and the quantum yield was high to 0.77±0.02. All the characteristics indicated that MgSrAl10O17:Eu2+ would be a promising blue phosphor for PDP application. 相似文献
In this paper, the optical properties of a novel organic, 2,8-di(t-butyl)-5,11-di[4(t-butyl) phenyl]-6,12-diphenylnaphthacene (tetra(t-butyl)rubrene) have been investigated. Our results show that there are two peaks in the photoluminescence (PL) spectra of tetra(t-butyl)rubrene (TBRb) which are also confirmed in the electroluminescence (EL) spectra. Photo-quenching of the PL intensity is observed when the irradiation time increases. It is shown that oxidation is the dominant reason for photo-quenching. The absolute refractive index and absorption coefficient have also been determined and the results correlate well with the PL results. The results show that TBRb can be a good dopant to achieve the Förster energy transfer and to assist light emission. The optical properties of TBRb are similar to those of rubrene; however, the PL of TBRb is much stronger than that of rubrene. Finally, although crystalline organics have been commonly reported by heating the sample, we report crystallization of TBRb at low temperature <230 K when the TBRb film is in an amorphous form before cooling. PACS 78.47.+p; 78.55.-m; 81.05.Lg; 85.60.-q 相似文献
In recent years, optical vortex beams possessing orbital angular momentum have received much attention due to their potential for high‐capacity optical communications. This capability arises from the unbounded topological charges of orbital angular momentum (OAM) that provide infinite freedoms for encoding information. The two most common approaches for generating vortex beams are through fork diffraction gratings and spiral phase plates. While realization of conventional spiral phase plate requires complicated 3D fabrication, the emerging field of metasurfaces has provided a planar and facile solution for generating vortex beams of arbitrary orbit angular momentum. Among various types of metasurfaces, the geometric phase metasurface has shown great potential for robust control of light‐ and spin‐controlled wave propagation. Here, we realize a novel type of geometric metasurface fork grating that seamlessly combine the functionality of a metasurface phase plate for vortex‐beam generation, and that of a linear phase gradient metasurface for controlling the wave‐propagation direction. The metasurface fork grating is therefore capable of simultaneously controlling both the spin and the orbital angular momentum of light.
By virtue of the electron‐donating and electron‐withdrawing properties of the thiazole ring, a new soluble rigid‐rod organometallic polymer containing electron‐donating and electron‐withdrawing trans‐[‐Pt‐(PBu3)2‐C≡C—R—C≡C—]n (R = bithiazolediyl) groups is prepared by CuI‐catalyzed dehydrohalogenation. The thermal properties and the optical absorption and photoluminescence spectra of the polymer are reported. The polymer is luminescent with a singlet emission peak at 539 nm and photoconducting in a single‐layer sandwich structure photocell. The optical gap of the polymer is reduced compared to that for the oligothienyl analogue. 相似文献
An efficient synthetic strategy to mono- and bis-glyoxylamide derivatives via the reaction of N-acylisatins with a range of amino acids has been developed. Using this strategy, a series of new peptidomimetics have been synthesized. 相似文献