High-quality zinc selenide (ZnSe) single crystals were grown by the high-pressure Bridgman method (HPB). Physical vapor transportation (PVT) method was adopted to purify ZnSe (4N) polycrystalline materials. The purity of starting material can be improved to 5N after the purifying process. The effect factors of purifying temperature, oxygen percentage and pressure etc. to the crystal growth were studied. The homogeneity analysis shows that the ZnSe single crystals obtained are highly homogenous and integral. Optical properties analysis shows that the transmittance coefficient of ZnSe single crystal is above 70%, with high refractive index and low absorption coefficient.
In this paper electron trapping optical storage materials CaS: Eu, Sm was prepared by high temperature solid state method. XRD analysis indicates that the sample obtained is with face-centered cube structure. with a lattice parameter of 5.694A. Optical properties of CaS: Eu, Sm were studied. Excitation spectrum shows that the material can be excited by ultraviolet and visible light. The excitation peaks are at 250-300nm and 450-550nm respectively ranging from 250-550nm. Emission spectrum is composed of three peaks at 567nm, 603nm and 650nm respectively. Photo-stimulation excitation spectrum is a broadband spectrum between 800nm and 1600nm peaking at about 1200nm. Photo-stimulated luminescence peak is at 635nm.
In this paper, rare earth europium ion doped SrO-B2O3-Al2O3-SiO2 glasses were prepared. The batches were melted under an ambient atmosphere and reheated under a reducing atmosphere. The glass after being reheated in the reducing atmosphere show long after glow phosphorescence resulted from 5d-4f transition of Eu2+ ion . Whereas the glasses melted under an ambient atmosphere show luminscence peaks attributed to the 5Di→7Fj of Eu3+ ion.
In this paper, we prepared SrAl2O4:Eu2+,Dy3+ long persistence phosphorescence enamel coatings by using SrAl2O4:Eu2+,Dy3+ phosphor powders and glass frits and organic vehicle. The glass frits were specially prepared to fit the SrAl2O4:Eu2+,Dy3+. The prepared phosphorescence enamels were found to have very bright long lasting phosphorescence after being excited by the ordinary fluorescent lamp or sunlight. The emission can be seen even 12h after removal of the exciting soruce. The emission shows a broad band peaking at 520nm resulted from the transition of 4f-5d of Eu2+ ions in SrAl2O4:Eu2+,Dy3+. The phosphorescence enamels can be used as energy saving display in various applications.