The Research Of Deep Red And Near-infrared Emitting Material Under Excitation Of Blue Light

This work is focused on solving these problems, such as the complex process, nano is difficult to make and low intensity of deep red luminescent material, and the range of excitation is narrow, near-infrared intensity is low and the application is limit of near-infrared emitting material under excitation of blue light and so on. We prepared K2 Si F6:Mn4+ and K2 Sn F6:Mn4+ nano phosphor through a fast liquid–solid solution route at room temperature, and prepared YAG:Ce,Cr,Yb near-infrared emitting phosphor by ?ring host and activated materials at high temperatures. K2 Si F6:Mn4+ and K2 Sn F6:Mn4+ nano phosphor and YAG:Ce,Cr,Yb near-infrared emitting phosphor have higher performance than traditional materials.In the second chapter, we research K2 Si F6:Mn4+ and K2 Sn F6:Mn4+ nano phosphor through a fast liquid–solid solution route at room temperature. The XRD date proves that nano phosphors are indexed to JCPDS card. At the same time, the size is uniform, the property of luminescent and stability are superior, and application is also wide. At the first, several important synthetic factors are investigated, including KOH/oleic acid quality ratio, different kinds of surfactants, Si O2 spheres/KMn O4 molar ratio or Sn O2 /KMn O4 molar ratio and reaction time and so on. When KOH/oleic acid quality ratio is changed from 0.5:1 to 2.5:1, K2 Si F6:Mn4+ samples are changed from 1~2 mm particles to a length of about 10 μm and a width of about 100 nm nanorods, K2 Sn F6:Mn4+ samples are changed from 1 mm particles to a length of about 4 μm and a width of about 200 nm nanorods; When Si O2 spheres/KMn O4 molar ratio changes from 1:0.5 to 1:50, K2 Si F6:Mn4+ samples grow from length of 200 nm, width of 70 nm nanorods to 1~2 mm particles,while, Sn O2 /KMn O4 molar ratio changes from 1:1.5 to 1:40, K2 Sn F6:Mn4+ samples grow from length of 100 nm, width of 50 nm nanorods to 1 mm particles; The length of K2 Si F6:Mn4+ nanorods are adding along with the increasing of reaction time. Secondly, in the performance, When KOH/oleic acid quality ratio is 2.5:1, Si O2 spheres/KMn O4 molar ratio is 1:10 and reaction time is 30 min, K2 Si F6:Mn4+ nano materials have super performance; When KOH/oleic acid quality ratio is 2.5:1, Sn O2 /KMn O4 molar ratio is 1:5 and reaction time is 30 min, K2 Sn F6:Mn4+ nano materials have excellent performance. Finally, K2 Si F6:Mn4+ and K2 Sn F6:Mn4+ nano materials show superior performance than bulk materials, but K2 Si F6:Mn4+ nano materials compare to K2 Sn F6:Mn4+ nano materials, K2 Sn F6:Mn4+ nano materials are worthy studying because of excellent performanceIn the third chapter, we research YAG:Ce,Cr,Yb near-infrared emitting phosphor by ?ring. The XRD date proves that different doped YAG phosphors are indexed to JCPDS card. At the same time, YAG:Ce,Cr,Yb phosphors have some advantages, for example, wide excitation band from 300 nm to 750 nm, 1035 nm near-infrared emitting intensity is stronger, and application is wide. When the doping content of Yb is 5%, the doping content of Cr is 0.5% and the doping content of Ce is 6%, YAG:Ce,Cr,Yb phosphors show excellent performance. And we demonstrate that energy transfer occurring from Cr3+ to Yb3+ and from Ce3+to Yb3+. Ce3+ and Cr3+ absorb energy, which allows energy from ground state transition to excited state, but the electrons of excited state are not unstable, and return to ground state, emitting visible light. At the same time, it transfers some energy to Yb3+, which cause Yb3+ is transition from ground state 2F7/2 to excited state 2F5/2, and return to ground state agains, emitting near-infrared light. In application, YAG:Ce,Cr,Yb phosphors are applied for c-Si based solar cell, not only convert more sunlight and reduce loss, but also improve the photoelectric conversion efficiency of solar,which Jsc is 15.1%. Besides, YAG:Ce,Cr,Yb phosphors are also applied for laser,optical, military, materials analysis, infrared camouflage and biological monitoring and so on.