掺Bi钨酸镉单晶体发光特性的研究  

Luminescence of Bi-doped CdWO_4 single crystals

作　　者：罗彩香[1] 夏海平[1] 虞灿[1] 徐军[2] 

机构地区：[1]宁波大学光电子功能材料重点实验室,宁波315211 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《物理学报》2011年第7期768-773,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60777030;50972061);浙江省杰出青年科学基金(批准号:R4100364);宁波市自然科学基金(批准号:2009A610007;2010A610185);宁波大学王宽诚幸福基金资助的课题~~

摘　　要：用坩埚下降法(Bridgman)生长出了Bi离子掺杂的CdWO4单晶.测定了晶体不同部位的吸收光谱、发射光谱和X射线电子能谱(XPS).Bi离子的掺入引起CdWO4晶体的吸收边从345nm红移到399nm.在311nm,373nm,808nm和980nm光的激发下,分别观测到中心波长为470nm,528nm,1078nm和较弱的1504nm四个不同发射带.Bi:CdWO4单晶的XPS谱分别与Bi2O3(Bi3+)和NaBiO3(Bi5+)样品的进行比较,推断Bi3+和Bi5+离子同时存在于CdWO4晶体中.可见光波段的470nm与528nm荧光发射起因于CdWO4晶体基质中WO66-与掺杂于晶格中Bi3+离子的发光;而1078nm的发射峰则起因于Bi5+离子的发光.XPS的分析结果与荧光强度的变化一致,沿着晶体生长方向,1078nm的荧光强度逐步变弱,Bi5+离子的含量逐步减少;而位于528nm处的荧光强度则逐步增强,Bi3+离子的含量逐步增多.The bismuth-doped CdWO4 single crystals are prepared by the Bridgman method. The absorption spectra, emission spectra and X-Ray photoelectron spectroscopy （XPS） of various parts of as-grown Bi： CdWO4crystal are investigated. The absorption edge of CdWO4 crystal is red-shifted from 345nm to 399nm due to the introdution of Bi into crystal. The four emission peaks at 470, 528, and 1078 and a weak peak at 1504 nm are observed under the excitation of light beams at 311, 373, 808, and 980 nm. From the X-Ray photoelectron spectroscopic measurements of the Bi： CdWO4 single crystals, Bi2O3 （Bi^3＋ ） and NaBiO3 （Bi^5＋ ） samples, we infer that there coexit Bi^3＋. and Bi^5＋ in Bi： CdWO4 crystals. The fluorescence emissions of visible bands at 470 and 528 nm result from both WO66- in Bi： CdWO4 and Bi^3＋ ions doped in the lattice, while the fluorescence emission of the near infrared band at 1078 nm is due to the Bi^5＋ luminescence. The analysis result of XPS is consistent with the change of the fluorescence intensity： along the growing direction the emission intensity at 1078 nm and the content of Bi^5＋. ion both decrease gradually, while the intensity at 528 nm and the number of Bi^3＋ both increase gradually.

关 键 词：Bi离子 荧光光谱 X射线电子能谱 CdWO4单晶 

分 类 号：O782[理学—晶体学]