氨基磷酸辅助的水热合成NaYF_4∶Yb^(3+),Er^(3+)纳米晶及其上转换发光

AEP-assisted Hydrothermal Synthesis and Upconversion Luminescence of NaYF_4∶Yb^(3+),Er^(3+) Nanocrystals

以氨基磷酸为螯合剂,通过共沉淀与水热法相结合,成功地制备出NaYF4∶Yb3+,Er3+纳米晶。研究结果表明:水热前后NaYF4∶Yb3+,Er3+纳米晶均为立方相结构,其颗粒大小约为80 nm。在980 nm近红外光激发下,实现了样品的上转换发光。样品的上转换绿红光发射带归因于Er3+的2H11/2,4S3/2→4I15/2和4F9/2→4I15/2能级的跃迁。水热处理后的样品的上转换发光强度与水热处理前相比有了很大的增强。水热处理后,样品表面的有机配体的减少和样品结晶度的提高是样品上转换发光显著增强的主要原因。

NaYF4∶Yb3＋,Er3＋ nanocrystals were successfully prepared by the combination of coprecipitation and hydrothermal methods using 2-aminoethyl phosphate（AEP） as chelator.It is found that the crystal structures of the NaYF4∶Yb3＋,Er3＋ nanoparticles before and after hydrothermal treatment are both in cubic phase,the size of which is about 80 nm.The upconversion luminescence from the two samples was observed under the excitation of 980 nm laser.The green and red emission bands are attributed to the transition of 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 energy levels of Er3＋ ions,respectively.The upconversion luminescence intensity of the sample with hydrothermal treatment is much stronger than that of the sample without hydrothermal treatment due to the improved crystallization of the samples and the reduction of organic ligands on the surface of the NaYF4∶Yb3＋,Er3＋ nanoparticles.