【摘要】 采用共沉淀法制备了平均粒径约30nm的Y₂O₃:Er,Yb纳米晶,并对其可见-红外发光特性与体相材料的差别进行了对比.结果表明:焙烧温度的升高有利于纳米晶晶化程度增强.在980nm红外激发下,Er3+离子呈现典型的绿、红光上转换特征发射,峰位位于530,550,660nm,分别对应于2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2跃迁.同时观察到了源于Er3+离子4I13/2→4I15/2辐射跃迁的1 530nm红外发射.随焙烧温度的升高,各发射光强度随之增大.但Y₂O₃:Er,Yb纳米晶呈现明显不同于体相材料的发光特性,其红、绿光强度分支比可达19.55,是体相材料的5倍,红光色纯度优异.同时,红外发射强度亦远高于体相材料.上述结果反映出Er3+的4F9/2和4I13/2能级在Y₂O₃纳米晶中的粒子布居特征迥异于体相材料,其跃迁机制亦存在很大差别.更多还原

【Abstract】 The near-spherical Y₂O₃:Er3+,Yb3+nanocrystals（NCs）with average particle size of 30 nmwere prepared by coprecipitation method.The visible and infrared luminescence properties of the NCs were studied and compared with its correlative bulk material.XRD measurement result shows that a relative high calcining temperature is of benefit to improving the crystallization degree of the NCs.Under the excitation of 980 nm LD,the NCs exhibited characteristic upconversion emissions,which correspond to 2H11/2→4I15/2（530nm）,4S3/2→4I15/2（550nm）and 4F9/2→4I15/2（660nm）transitions,respectively.Simultaneously,a 1 530 nm infrared emission arise from4I13/2→4I15/2transition of Er3+ion was also be observed.It is obvious that all emission intensities showed a visible improvement as the calcining temperature was increased.However,distinct differences of luminescence character between NCs and its bulk correspondence could be observed.The intensity ratio of red and green emission for NCs can reach 19.55,which is 5larger than the bulk material.At the same time,the infrared emission intensity of the NCs is also much stronger than its opponent.These results indicated that the population of 4F9/2and 4I13/2levels,even the transition mechanism of Er3+in Y₂O₃:Er3+,Yb3+NCs are widely different with bulk material.更多还原