用水热法在低于300℃成功地制备出具有不同形貌的YBO3：Eu3+荧光粉，其反应温度比固相反应降低了约800℃。研究了初始原料、pH值、反应温度、反应溶剂和催化剂等条件对目的产物形貌及粒度的影响。得到了具有Vaterite结构、粒度分布均匀的球形荧光粉的最佳合成工艺。在254 rim激发下，水热法制备的球形Y Euo-o BO3荧光粉最强发射峰位于598rim处，属于Eu抖的 D。一的跃迁，是固相反应所得样品的1.5倍。这些结果表明，在PDP和荧光灯等显示和照明用荧光粉的制备中水热法具有潜在的应用前景。

Single phase europium-activated gadolinium aluminum borate, Gd1-xEuxAl3(BO3)4 (0<x<1) was obtained by the evaporation of its nitrate solution, and calcination at 900 to 1100C in air. All the solid solution was identified as the isomorphs of huntite. Eu31 activated GdAl3(BO3)4 showed intense red emission with CIE chromaticity coordinates of (0.645, 0.330) under 147nm excitation. According to the excitation and emission spectra, the red emission of Eu31 was decreased under excitation of the vacuum ultraviolet (VUV) region (158-160nm), and increased under excitation UV region (258-260nm) with the increase of Eu31 concentration. In comparison with the absorption data of borates, the 158 nm excitation peak was assigned to the energy level of BO3 groups. In excitation spectra, the sharp 274nm peak, corresponding to the 8S72→6I2/11 transition of Gd31 in addition to the f-f transitions of Eu31 were observed. Consequently, the emission of Eu31 was induced by the energy transfer of VUV excitation to the activator Eu31 ions via the co-activator Gd31 in GdAl3(BO3)4.

Vaterite-type GdBO3:Eu3+ phosphor was first prepared by using a mild hydrothermal method. GdBO3:Eu3+ phosphor was fairly controlled as high purity, homogeneous, stoichiometric, uniform plate morphology and nonaggregation powders. The typical powders were plate shaped and 1.6-2.0mm in size. As the synthesis temperature was below 300 C, the recovered phosphor had never been subjected to the phase transition to the calcite type during the chemical reaction. The phosphor showed the excitation band peaked at about 239nm, and the emission band peaked at about 591nm had twice the intensity compared with the conventional phosphor. The excitation and emission peaks were somewhat shifted to shorter wavelength. The GdBO3:Eu3+ phosphor showed maximum intensity in emission for the doped 20 at.% of Eu3+ upon 239nm excitation and 10at.% Eu3+ under 146nm excitation, respectively. Therefore, the energy relaxation pathway to the Eu3+ sites should be different. Also, the partial substitution of Y3+ for Gd3+ was very convenient to improve the emission intensity of Eu3+ under 146nm excitation, whereas the emission intensity was decreased with increasing Y3+ concentration under 239nm excitation.

anganese-doped zinc silicate powder samples were prepared successfully by solution combustion process, and their photoluminescence were investigated in ultraviolet region. The single-phase of Zn2-xSiO4: xMn (0≤x≤0.10, willemite) was obtained by combustion synthesis at 600℃for afew minutes, then heat treated at above 900℃ for 4h. In the excitation spectra of Zn2-xSiO4: xMn (0<x≤0.10), the strongest broad band at about 254nm is observed and as-signed to 6A1→4T1 transition of Mn2+ monitoring at 525nm emission. At about 525nm, the intense broad band emission is observed under 254nm excitation in Zn2-xSiO4: xMn (0<x≤0.10). This broad band is attributed to 4T1→6A1 transi-tion of Mn2+. The results indicate that photoluminescence efficiency, the location of the strongest excitation or emission band, and the optimum concentration of activator depend on starting materials, combustion temperatures, the dosage of fu-els, and the size of powder samples etc.

The luminescent properties of Ca4GdO(BO3)3: Eu3+ were investigated under excitation of UV and VUV light. Separate two broad bands at around 259 and 184nm were observed in the excitation spectrum of Ca4GdO(BO3)3: Eu3+. These peaks were assigned to the charge transfer transition of Eu3+-O22 and Gd3+-O22, respectively. Owing to the favorable spectral position in their broad intense excitation band, Eu3+ ions show a intense emission under 258nm excitation in Ca4GdO(BO3)3: Eu3+. This spectral position was determined by the free oxygen ions O (1). Ca4GdO(BO3)3 doped with Eu3+ ion seems to be a preferable candidate as red lamp phosphor. On the other hand, a weak band with a maximum at about 184 nm was observed below 200 nm in the excitation spectrum of Ca4GdO(BO3)3: Eu3+. This phosphor do not emit effectively under the 147 nm excitation. This unfavorable profile was also due to the O (1) ions, which played a role to the shifting towards the lower energy sides. The luminescence of Eu3+ ions in Ca4GdO(BO3)3 was somewhat different from that observed in the other borates phosphors, but resembled to those observed in the oxide phosphors (e.g. Gd2O3, Y2O3 and Gd2SiO5). Such behavior was recognized by the detailed analysis of crystallographical surroundings around activator.