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Study on the Up-conversion Green Light Properties in Ho3+/Yb3+/Ce3+-codoped LiTaO3 Polycrystals

Author: HaoMing
Tutor: ShiLianSheng
School: Harbin University of Science and Technology
Course: Materials Processing Engineering
Keywords: High temperature solid phase LiTaO3: Ho3 / Yb3 / Ce3 Upconversion luminescence Upconversion mechanism
CLC: O734
Type: Master's thesis
Year: 2011
Downloads: 15
Quote: 0
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Abstract


High-temperature solid phase was prepared by a series of different doping concentration of rare earth ions LiTaO 3 polycrystalline. X-ray diffraction test results show that the doping LiTaO 3 polycrystalline sample is a single phase. Combination of X-ray diffraction and UV - visible spectrum Ho 3 the Yb 3 and of Ce of 3 ions exist in the alternate form of bits LiTaO 3 lattice, rather than of the lattice spacing. Excitation of the 980nm pump light source, in the LiTaO 3 : the Ho 3 / Yb 3 series of polycrystalline samples were observed in the visible region than strong upconversion red the upconversion green and weak emission. With Ho 3 and the Yb 3 ion concentration increased, upconversion red, have a corresponding increase in the emission intensity of green light, however, Ho 3 < / sup> or the Yb 3 ion doping concentration is too high will weaken upconversion green, red emission intensity. In the LiTaO 3 : the the Ho 3 / Yb 3 system based on Ce 3 ions found enhanced upconversion green and suppress upconversion red, green monochrome can effectively improve the conversion. XRD pattern results showed that the prepared powders still trigonal system. Excitation of the 980nm pump light source, in the LiTaO 3 : the the Ho 3 / Yb 3 / Ce 3 Series polycrystalline samples, we found that the upconversion green emission intensity with Ce 3 ion doping concentration increased and enhanced, and Ce 3 ion doping concentration of 15mol% realized on the conversion monochrome green output at this time the Ho 3 , the Yb 3 the Ce 3 doping concentration were 1mol%, 10mol% , and 15 mol%, respectively. Ce 3 ions and Ho 3 ion cross relaxation the Henan process: 5F3 (Ho 3 ) F < sub> 5/2 (Ce 3 ) → 5F4/5S2 (Ho 3 ) 2 F 7/2 (Ce 3 ) 5I7 (Ho 3 ) F 7/2 (Ce < sup> 3 ) → 5I6 (Ho 3 ) 2 F 5/2 (Ce 3 ) significantly enhanced upconversion green luminescence intensity. Highly doped Ce 3 ion cross relaxation process 5F5 (Ho 3 ) 2 F 7/2 < / sub> (Ce 3 ) → 5F4/5S2 (Ho 3 ) 2 F 5/2 (Ce 3 ) is to enhance the green and red light while suppressing the effective way.

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CLC: > Mathematical sciences and chemical > Crystallography > Crystal physics > The optical properties of the crystal
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