Improvement of properties of single-phase-white-light-emitting (La0.97Pr0.03)VO4 phosphor

• Main Authors: MA, HAO-LUN, 馬浩倫
• Other Authors: CHANG, YEE-SHIN
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/zvcta9

碩士 === 國立虎尾科技大學 === 電子工程系碩士班 === 106 === In this study, La(0.97)Pr(0.03)VO4 phosphor was prepared as the host material by sol-gel method. The first part was the host of phosphor with La(0.97)Pr(0.03)VO4. Different concentrations of Urea were added. The nitrogen ion in Urea replaces the oxygen ion in the host lattice to improve the luminescent properties of its phosphor powder. In the second part, La(0.97)Pr(0.03)VO4 was also used as the host of the phosphor, and different concentrations of PEG 2000 were added to investigate the influence of the doping concentration on the surface morphology and luminescent properties of the particles. In the first part, XRD results show that the structure is monoclinic LaVO4 crystal structure under the condition of holding temperature of 950 °C for 6 hours. With the increase of the concentration of urea added, no secondary phase was observed. In the SEM analysis, the surface morphology of the phosphor powder is mostly irregular sheet agglomeration. Under 315 nm excitation, the emission spectrum consists of 3P0→3H4,5,6,1D2→3H4 and 3P0→3F2 electronic transitions of Pr3+ ions. When the urea concentration 10 wt.%, the Pr3+ ion 3P0→3H4 electron transition intensity in the range of 480~510 nm is the strongest. The CIE chromaticity coordinates are located near the white light region with the increase of the urea concentration. In the second part, the results of XRD analysis showed that the structure was monoclinic LaVO4 crystal structure under the condition of holding temperature at 950°C for 6 hours. With the increase of PEG 2000 concentration, no secondary phase was observed. In the SEM analysis, the surface morphology of phosphor powder changed from irregular flakes to spherical particles with increasing concentration of PEG 2000. Under 315 nm excitation, the emission spectrum consists of 3P0→3H4,5,6,1D2→3H4 and 3P0→3F2 electronic transitions of Pr3+ ions. When the concentration of PEG 2000 10 g, the electronic transition of Pr3+ ion 3P0→3H4 in the range of 480~510 is the strongest. The CIE chromaticity coordinates shift from magenta to near white as the concentration of added PEG 2000 increases, and then shifts to the near-yellow position.