The Study Of Sulfide Doped With Rare-Earth Optical Storage Materials

In recent years, with the rapid development of laser and optical storage technology, alkaline earth sulfide (AES) doped with rare earth has aroused peoples' attention. It has two following important properties: one is optical storage, that is, optical signals can be stored in trap electron form for long time, the other is infrared up-conversion, that is, it can convert infrared to visible light at room temperature. So people call this kind material as electron trapping infrared up-conversion and optical storage material, too. As a new type optical storage material, it has momentous applied value in many aspects, such as super-condense and super-speed disc storage, image storage, information treatment, optical calculation, infrared detection, infrared up-conversion imaging, radiation dose measurement, etc.In this paper, we prepared CaS: Eu,Sm SrS: Eu,Sm and CaSrS: Eu,Sm materials with excellent optical storage properties by wet method prepared precursor and followed rare earth direct doped method in reduced atmosphere. A series of preparation conditions and parameters were systematically studied. It is concerned that the effects of prepared method of precursor, material synthesize method, fired atmosphere, fired temperature, fired time, flux kind and content, rare earth concentration and kind and matrix on the microstructure and optical storage properties of the samples. At the same time, the optical storage mechanism was discussed in certain extent.XRD patterns, excitation spectra, emission spectra, photo-stimulated emission spectra, photo-stimulated emission decay curves and thermo-luminescence spectra have been measured on the samples. The results indicate that the samples (CaS: Eu,Sm SrS: Eu,Sm and CaSrS: Eu,Sm) are all facial cubic structure. Excitation spectra have peaks in the ultraviolet which means the ultraviolet can be information input resource and CaS: Eu,Sm has a weak peak at 420nm in the visible area which means information can be writen into it by visible light. Emission spectra include three linetype emissions of Sm3+. When the samples are stimulated by 580mW 980nm semiconductor laser, photo-stimulated emission spectra are broad bands peaking at 635nm, 599nm and 615nm, respectively. It indicates that 980nm can be read resource and the read-out signal wavelength are 635nm, 599nm and 615nm, respectively. The intensity of photo-stimulated luminescence decay with the infrared-stimulated time. It's to say the intensity of read-out signal weaken with the infrared-stimulated time. The peak of CaS: Eu,Sm in its thermo-luminescence spectrum is 420℃, SrS: Eu,Sm and CaSrS: Eu,Sm have no peaks in the measurement scale of instrument (20 ~ 500℃) which show the traps of the samples are so deep that electrons can not be released easily and information is stored steadily. CaS: Ce,Sm and CaS: Yb,Sm samples were prepared through changing rare earth kind, CaxSr1-xS:Eu,Sm (x=0, 0.25, 0.5, 0.75, 1), Ca0.45Sr0.45M0.1S: Eu,Sm (M=Mg, Ba), MO:Eu,Sm(M=Ca, Zn) were prepared through changing matrix, and then the evident influence on the optical storage properties of the samples were observed.The systematically study of the preparation of alkaline earth sulfide system doped with rare earth and its optical storage properties not only expand new synthesize technology of electron trapping optical storage materials but also afford basis for improving materials properties and application in different application fields.