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以碳酸氢铵为沉淀剂,采用共沉淀法制备了Er,Yb:(La Gd)2O3纳米粉体。经1 000℃煅烧2 h得到的粉体颗粒呈规则球形,平均粒径约为90 nm,团聚低,分布均匀。研究了Er3+,Yb3+的掺杂量对样品发光强度的影响。结果表明:掺杂Er3+和Yb3+的摩尔分数分别为4%和5%时,所得样品的发光性能最优。样品的激发和发射光谱显示:在379 nm处激发峰最强,对应Er3+的4I15/2→4G11/2能级跃迁;最强发射峰位于562 nm处,对应于4S3/2/2H11/2→4I15/2能级跃迁。样品的上转换光谱表明:样品在548和662 nm有较强的发射峰,对应Er3+的4S3/2/2H11/2→4I15/2跃迁和4F9/2→4I15/2跃迁。并讨论了发光跃迁机制。
With ammonium bicarbonate as precipitating agent, Er, Yb: (LaGd) 2O3 nanopowders were prepared by coprecipitation method. The particles obtained after calcined at 1000 ℃ for 2 h have a regular spherical shape with an average particle size of about 90 nm and low agglomeration and uniform distribution. The effects of Er3 + and Yb3 + doping on the luminescence intensity of the samples were investigated. The results show that the luminescent properties of the obtained samples are the best when the mole fractions of Er3 + and Yb3 + are 4% and 5% respectively. The excitation and emission spectra of the sample show that the excitation peak is the strongest at 379 nm, which corresponds to the 4I15 / 2 → 4G11 / 2 level transition of Er3 +. The strongest emission peak is at 562 nm, corresponding to 4S3 / 2 / 2H11 / 2 → 4I15 / 2 level jump. The up-conversion spectra of the samples show that the samples have strong emission peaks at 548 and 662 nm, corresponding to 4S3 / 2 / 2H11 / 2 → 4I15 / 2 transitions and 4F9 / 2 → 4I15 / 2 transitions of Er3 +. The mechanism of luminescence transition is also discussed.