Er^(3+)和Ce^(3+)/Ce^(4+)掺杂β-BaB_2O_4纳米棒的制备、结构与发光性质

Preparation,Structure and Photoluminescence of Er^(3+) and Ce^(3+)/Ce^(4+) Doped β-BaB_2O_4 Nanorods

以Ba(NO3)2、NaBH4、Er2O3和CeO2为原料,在十六烷基三甲基溴化铵(CTAB)表面活性剂辅助下,采用水热法制备了β-BaB2O4(β-BBO)纳米棒,稀土离子Er3+单掺杂的β-BBO(β-BBO:Er3+)及Er3+和Ce3+/Ce4+共掺杂的β-BBO(β-BBO:Er3+/Ce3+/Ce4+)纳米棒.通过X射线粉末衍射(XRD)、傅里叶变换红外(FTIR)光谱、拉曼光谱、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和光致发光(PL)光谱分别对样品的物相、结构、形貌、成分及光致发光性质进行了表征.研究结果表明:微量稀土离子掺杂并不改变β-BBO的结构,制得的纳米棒尺寸均匀,长度在200-500nm之间,直径在10-20nm之间;β-BBO:Er3+和β-BBO:Er3+/Ce3+/Ce4+纳米棒在400nm光激发下,在可见光范围内都观察到中心波长为515和542nm的绿光.对发光机理的初步研究表明:发光分别对应于Er3+的2H11/2→4I15/2,4S3/2→4I15/2跃迁,铈离子以Ce3+和Ce4+两种形式存在于体系中,Ce3+对Er3+起敏化作用,可以显著增强β-BBO:Er3+/Ce3+/Ce4+纳米棒的发光强度,存在Ce3+→Er3+的能量传递过程.

β-BaB2O4 （β-BBO） nanorods,rare earth ion Er^3＋ doped （β-BBO：Er^3＋） and Er^3＋,Ce^3＋/Ce^4＋ co-doped （βBBO：Er^3＋/Ce^3＋/Ce^4＋） nanorods were synthesized by the cetyltrimethylammonium bromide （CTAB） assisted hydrothermal method using Ba（NO3）2,NaBH4,Er2O3,and CeO2 as raw materials.The as-prepared products were studied by X-ray powder diffraction （XRD）,Fourier transform infrared （FTIR） spectroscopy,Raman spectroscopy,scanning electron microscopy （SEM）,transmission electron microscopy （TEM）,X-ray photoelectron spectra （XPS）,and photoluminescence （PL） spectroscopy.Results indicate that the structure of the β-BBO nanorods doped with Er^3＋,Ce^3＋/Ce^4＋ was unchanged.The obtained nanorods have uniform diameters of 10-20 nm and lengths of 200-500 nm.Upon excitation with 400 nm light,the doped β-BBO nanorods exhibit a strong green light emission.PL spectra indicate that the emission bands at 515 and 542 nm correspond to the ^2H11/2→^4I15/2 and ^4S3/2→^4I15/2 transitions of Er^3＋,respectively.In the samples,the cerium dopant exists as Ce^3＋ and Ce^4＋.Ce^3＋ sensitizes Er^3＋ and enhances the luminescence intensity of the doped nanorods remarkably and energy transfer from Ce^3＋→Er^3＋ was observed.