Si^(4+)掺杂对橙红色荧光粉NaBaSi_xP_(1-x)O_4:Eu^(3+)结构和发光性能的影响

Effect of Si^(4+) Doping on Structure and Luminescence Properties of Orange-red Light-emitting Phosphors of NaBaSi_xP_(1-x)O_4:Eu^(3+)

采用高温固相法合成了一系列NaBaSi_xP_(1-x)O_4:Eu^(3+)橙红色荧光粉。表征了荧光粉的晶体结构和发光性能。考察了煅烧温度和Si^(4+)掺杂量对荧光粉结构和发光性能的影响。结果表明:掺杂Si^(4+)对荧光粉的晶型没有明显影响,但是导致了晶格膨胀。750℃煅烧时基质已形成NaBaPO_4相,晶型为六方晶系,荧光粉发射峰强度最强。激发光谱由200~280 nm的宽带和310~500 nm的一系列尖峰组成,分别对应于O^(2–)→Eu^(3+)电荷迁移带和Eu^(3+)的f→f能级跃迁吸收,最强激发峰位于393 nm左右,与近紫外LED芯片的发射光谱匹配。在393 nm近紫外光激发下,最强发射峰和次强发射峰分别位于红光616 nm和橙光591 nm附近,分别属于Eu^(3+)的~5D_0→~7F_2和~5D_0→~7F_1特征跃迁。NaBa_(0.92)Si_xP_(1–x)O_4:0.08Eu^(3+)中Si^(4+)的最佳掺杂量为0.02 mol,Na Ba_(0.92)Si_(0.02)P_(0.98)O_4:0.08Eu^(3+)样品在616和591 nm附近的发射强度比单掺杂Eu^(3+)的样品分别提高了66.6%和63.6%。

Orange-red light-emitting phosphors NaBaSixP1-xO4：Eu3＋ were synthesized by a high-temperature solid-state method. The crystal structure and luminescence properties of the phosphors were characterized. The effects of calcination temperature and Si4＋ doping amount on the crystal structure and spectra properties of the phosphors were investigated. The results indicate that doped Si4＋ has no obvious influence on the crystal form of phosphors, but leads to the expansion of the lattice. After the calcination at 750 ℃, the structure of the matrix crystal is formed, belonging to a hexagonal crystal system, and the luminescence intensity of phosphors is the most intense. The excitation spectra includes a broadband in the range of 200-280 nm and a series of spikes in 310-500 nm with the maximum excitation peak of wavelength at 393 nm that matches with the near ultraviolet （UV） LED chip, and each peak belongs to O2→Eu3＋ charge transfer band and f→f energy level transition of Eu3＋, respectively. Under the near UV excitation at 393 nm, the maximum emission peak and the sub-maximal emission peak appear near-red light at 616 nm and orange light at 591 nm, which belong to 5D0→7F2 and 5D0→7F1 transition of Eu3＋, respectively. The optimum doping amount of Si4＋ in NaBa0.92SixP1-xO4：0.08Eu3＋ is 0.02 mol, the emission intensities of Eu3＋ at 616 and 591 nm in NaBa0.92Si0.02P0.98O4：0.08Eu3＋ sample are 66.6% and 63.6%, which are greater than those of NaBa0.92PO4：0.08Eu3＋ sample.