BaMgF_4:Er^(3+),Yb^(3+)上转换纳米晶的合成及其发光性能研究

Synthesis and upconversion luminescent properties of BaMgF_4: Er^（3+）, Yb^(3+)nanocrystals

采用反向共沉淀法制备了形貌呈棒状的BaMgF4:Er3+,Yb3+上转换纳米晶.样品在980 nm半导体激光器激发下发射绿色和红色上转换荧光,其发射的绿、红发射带归因于Er3+离子的2H11/2—4I15/2,4S3/2—4I15/2和4F9/2—4I15/2跃迁.当Er3+的掺杂浓度为3%,Yb3+离子掺杂浓度为10%时,荧光粉的上转换发光强度最强;随着Yb3+离子浓度的增加样品的红光发射增强,绿光发射减弱.通过上转换发光强度与抽运电流关系曲线的拟合,得出BaMgF4:Er3+,Yb3+上转换材料的绿光与红光的上转换过程均为双光子吸收过程.

BaMgF4 ：Er3＋, Yb3＋ nanocrystals in rod-shape are synthesized by means of the reverse co-precipitation. They emit green and red light under excitation of near-infrared light （980 nm）. The green and red emissions may be attributed to the 2H11/2-4I15/2, 4S3/2-4I15/2 and 4F9/2-4I15/2 transitions of Er3＋. Dopant ions Yb3＋ as sensibilizers can improve the upconversion transformation efficiency. The emission intensity is the strongest when the contents of Er3＋ and Yb3＋ are 3% and 10%, respectively. With increasing concentration of Yb3＋, the red emission intensity increases while the green emission reduces. And the conversion fitting curve between the luminous intensity and pump current indicates that the upconversion process of the green and red light of BaMgF4 ： Er3＋, yb3＋ is due to two-photon absorption.