【摘要】 采用共沉淀法制备了Er3+掺杂和Er3+/Yb3+共掺杂LaF3超微材料,所制备的样品的颗粒呈球形,尺寸为250nm左右.计算得到Er3+单掺杂样品中对应着4S3/2和4F9/2能级的发光量子效率分别为67.0%和71.9%.研究发现,随着Yb3+离子浓度的增加,Yb3+离子向Er3+离子能量传递作用增强,导致上转换荧光强度随激发功率的增加而增加的程度变缓.同时由于Yb3+离子向Er3+离子敏化能量传递作用增强也使得Er3+离子之间能量传递作用的加强,并导致红、绿强度比随Yb3+离子浓度增加而增加.更多还原

【Abstract】 Er3+ doped and Er3+/Yb3+ co-doped superfine LaF₃ powders are prepared using co-precipitation method.The sample shows spherical particles with size of about 250nm.The quantum efficiencies of 4S₃/2 and 4F₉/2 levels in the prepared Er3+ doped LaF₃ powders are calculated to be 67.0% and 71.9%,respectively.With the enhancement of the Yb3+ doping concentration,The upconvertion intensity increases as a function of excitation power more slowly due to the enhancement of the sensitization of Yb3+ to Er3+.The Er3+_Er3+ interaction is also reinforced as the Yb3+ concentration increases.This leads to the increase of the ratio of the green emission to the red one with the enhancement of Yb3+ concentration.更多还原