Study on the Vacuum Ultraviolet Spectroscopic Properties of Bismuth Vanadium Borate Phosphors

The color plasma flat panel display (PDP) uses vacuum discharges such as helium and neon to generate 100 to 200 nm vacuum ultraviolet (VUV) radiation to excite three-color phosphors to achieve luminescent display. The picture quality of the PDP device largely depends on the performance of the phosphor, and the PDP phosphor has been developed from the conventional lamp powder, and the luminescence performance is defective. In recent years, the research of phosphors for PDPs has received extensive attention from luminescent material researchers. The rare earth borate has good transparency in the ultraviolet-vacuum ultraviolet region and is an excellent phosphor matrix material. However, when Eu3+ is used as an activating ion, Eu3+ is emitted by a 5D.-7F1 transition because it occupies the central symmetry position of the matrix. 593nm, orange light) dominated. In order to make the red-emitting 5D0-7f2 transition to be the main emission, one of the methods is to introduce other ions in the borate matrix to transform the centrally symmetrical matrix structure into non-central symmetry. Therefore, there is a matrix near 150 nm. The sensitized bismuth vanadate is a good candidate material. In this paper, Y23, Eu23, V25 and H3B3 were used as raw materials. YBxV1-x4-x:Eu3+ phosphors were synthesized by high temperature solid-state reaction. The obtained powders were characterized by XRD, UV laser excitation and vacuum ultraviolet excitation and emission spectra. The study found that: BO3-in the sample matrix can reduce the luminescence quenching temperature; YBxV1-x4-x:Eu3+ phosphor emission peak is located at 619nm, the color purity is good, and the luminescence brightness reaches (Y,Gd)BO3:Eu3+ commercial powder 86%. 2 Experiment (AR), H3BO3 (AR) as raw materials, according to the stoichiometric ratio (H3BO3 taking into account the volatility of the excess of 10% to 15%) Weigh a certain amount in the Ma wall mortar fully grinding uniform, and then loaded In the corundum crucible, YBxV1-x4-x:Eu3+ phosphor samples were obtained after being fired in air at 1050-1200°C for 2 hours. The X-ray diffraction (XRD) spectrum of the sample was measured using an X-ray diffractometer from Japan's Ricoh Electric Corporation's 0/ma)-RA rotary Cu target; the morphology of the sample was measured using a KYKY-1000B scanning electron microscope from Beijing Scientific Instrument Factory. The variable-temperature emission spectra of the samples of the LABRAM-UV ultraviolet optimized micro-area Raman spectrometer from Jobh-Yvon, France; the emission spectra and excitation spectra of the sample under vacuum ultraviolet light (VUV) excitation were studied at the Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The vacuum ultraviolet spectrometer developed on the test.

3 Results and discussion Soil, molybdenum, vanadium and other metal oxides can be mutually soluble at a certain temperature, resulting in a glassy or solid solution. We performed X-ray powder diffraction (XRD) analysis of the YBx x:Eu3+ sample prepared under the same conditions. The results showed that the XRD data of the YBO3:Eu3+ sample matched the JSP-DS standard card 741929 and was a hexagonal crystal. The YVO4:Eu3+ data is in good agreement with 7-1649 and is in the tetragonal system; the XRD data for the YBxV1-x4-x:Eu3+ sample indicates that it should be a mixture of YBO3:Eu3+ and YV4:Eu3+ rather than a compound.

: Effect of different burning temperature on the emission spectrum of Eu3+3.2: Eu3+ phosphor gradually becomes whiter. The emission spectra of the phosphor samples obtained under different ignition temperatures were excited by vacuum ultraviolet (VUV) at 147 nm. It can be seen that under the excitation of VUV, the main emission peak of the phosphor is located at 619 nm, and the 5D―7F2 emission from Eu3+ ion is a red emission; with the increase of the ignition temperature, YBxV1-x4-x:Eu3+ The luminescence intensity of the phosphor is continuously enhanced, which is related to the increase of the crystallinity of the phosphor particles as the temperature rises, but the emission intensity ratio of the 5D-7F1 enthalpy and the 5D-7F2 enthalpy are basically unchanged.

The emission spectra of YB.5V.53.5:Eu3+ phosphors were obtained at different calcination temperatures to determine the matrix composition. YBO3 incorporation into different proportions of YVO4 was tested. The emission spectra of YBxV1-xO4-x:Eu3+ phosphors with different V/B molar ratios at 147 nm VUV excitation. It can be seen that the main emission peak of YBO3:Eu3+ phosphor is from Eu3+ (5D). Therefore, the color purity of YBO3:Eu3+ phosphor is poor, and the color of emission is orange. After the matrix is ​​doped with YVO4, the spectrum changes greatly, and Eu3+ is 5D (). The "7-F ytterbium" emission is significantly weakened, and the 5D0-7-doped emission (619nm) becomes the dominant emission, and the shape of the spectrum changes greatly. With the increase of the YVO4 component, the 5D () FT emission of Eu3+ gradually weakens. , and 5D () 7F2 jump emission gradually increased, that fluorescence branch than R / O (red-orange ratio) increased. “F2 撄”; as the temperature increases, the probability of excitation energy transferred by the matrix to Eu3+ increases, the luminescence of Eu3+ gradually increases, and the luminescence of YB0.6V0.4O3.4:Eu3+ sample has temperature quenching phenomenon. The quenching temperature (417.65K) is higher than the latter (366.25K), indicating that the YBO3 doped with YBO3 can improve the temperature stability of the phosphor. Therefore, the appropriate B/V molar ratio must be considered when determining the composition of the matrix. .

The efficiency of the empty UV region is low, which may be related to the fact that no flux was used during the synthesis. Through the calculation of the corrected emission spectrum, the color coordinate of the commercial (Y,Gd)B3:Eu3+ phosphor was obtained as x=0.642, y=0.358, and the fluorescence branch ratio R/O (red to orange ratio) was 1.52; YB04V63.6:Eu3+ fluorescence The color coordinates of the powder are x=0.655, y=0.344, and the fluorescence branch ratio R/O (red-orange ratio) is 3.85. Thus, it can be seen that the color purity of the YB04V0.6O3.6:Eu3+ phosphor is obviously superior to the commodity ( Y, Gd) B3: Eu3+ phosphor. At the same time, the luminescence brightness of YB0.4V0.6O3.6:Eu3+ phosphor was calculated as 86% of (Y,Gd)BO3:Eu3+. This also shows that the YB0.4V0.6O3.6:Eu3+ phosphor has lower luminous efficiency. As a practical application, its performance still needs further research and improvement.

4 Conclusions YBxV1-x4-x:Eu3+ fluorescent powders were synthesized by high-temperature solid-state reaction. The XRD results showed that the samples should be YBO3::Eu3+ mixtures. The samples were subjected to UV laser-induced temperature-change emission spectroscopy. The BO3-in the matrix can reduce the quenching temperature of luminescence, and the appropriate B/V molar ratio must be considered when determining the composition of the matrix; the emission peak of YBxVi-x4-x:Eu3+ phosphor is located at 619nm, the color purity is good, and the luminescence brightness reaches 86% of the (Y,Gd)BO3:Eu3+ commercial powder is a candidate material for the red phosphor used in color PDPs, but the actual application still needs further study.

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