Preparation,Structure And Luminescence Properties Of Several Glass Ceramics For Illumination/Display Applications

White light emitting diodes?w-LED?,as the next generation new solid state lighting source,create a new chapter in the field of lighting and display due to their admirable merits of long lifetime,energy saving,and environment-friendly,etc.However,the traditional white LED technology has been unable to meet the increasing demand for high-quality,high-power green lighting and high-end display technology in recent years.On the one hand,the further development of white LED technology have been restricted as the aging of organic encapsulation materials caused by high-power chips in long-term heat irradiation environment and the missing content of red light components in YAG:Ce³⁺-based fluorescent conversion materials for the field of illumination.On the other hand,the lack of fluorescent conversion materials with stable thermochemical properties and high-efficiency narrow-band emission has long plagued researchers in various countries for the field of display.This paper aims to develop new color-adjustable glass ceramics for the application of high-power warm w-LED and perovskite glass ceramics for the application of wide-gamut LED.The research contents can be summarized as follows:?1?The chromaticity-adjustable glass ceramic were prepared by co-sintering Sn-P-F-O glass powder with the commercialized yellow YAG:Ce³⁺and red CASN:Eu²⁺phosphors.The glass ceramic material substantially maintains the excellent luminescence properties of the original phosphor such as the fluorescence quantum efficiencies of YAG:Ce³⁺-based glass ceramics and CASN:Eu²⁺reached 92.0%and 88.6%due to the weakening thermal erosion of the glass melt on the phosphor by the reasonable design of material composition and the optimization of preparation process.The bi-phase fluorescent crystallite-containing glass ceramic is coupled with the blue chip to package the white LED light source.The device light output from cold white to warm white can be achieved by changing the relative proportion of the yellow-red phosphor and the thickness of the glass ceramic layer.Driven by a current of 350 mA,the luminous efficiency is 90.71 Im/W and the color temperature is 3554 K.It is proved that glass ceramics have excellent thermochemical stability and can be applied to high-power lighting fields by an accelerated aging experiments.?2?A novel stress-responsive PPNCS glass?glass component:45P₂O₅-20PbBr₂-10NaBr-13Cs₂O-12SrO?was prepared by conventional melt quenching.When a dynamic force?kneading fracture or crushing grinding?is applied,CsPbBr_3-xI_x perovskite nanocrystals are precipitated on the surface of the glass.The force-induced crystallization mechanism of the glass of the system was systematically studied.We believe that the energy generated by the breakage of the glass bond chain induces the nucleation and growth of CsPbX₃?X=Cl,Br,I?nanocrystals in the glass,shear slip.Efficient ion transport with the ions avoids the long-range diffusion of ions required in traditional thermal crystallization;and glass phase separation and loose glass network structure also provide good conditions for the occurrence of force crystallization.Compared with the liquid phase synthesized CsPbBr₃ colloidal nanocrystals,the thermal and optical stability of CsPbBr₃ glass ceramics are greatly improved,and the synthetic route is more environmentally friendly and easy to prepare in large quantities.The CsPbBr₃ glass ceramic powder/commercial K₂SiF₆:Mn⁴⁺red phosphor and the blue chip are coupled into a white LED display light source.The color gamut of w-LED device can reach 99.4%NTSC,which proves the potential application for wide color gamut backlight display.In addition,based on this unique glass crystallization method,we explored the application of materials in dynamic force visualization,such as force sensing and Pb²⁺ion detection.