采用静电纺丝技术制备了PVP/[Y(NO3)3+Er(NO3)3]复合纳米纤维,经过氧化焙烧得到Y2O3∶Er3+纳米纤维,再通过双坩埚氟化法制得YF3∶Er3+纳米纤维.通过XRD、SEM、EDS和荧光光谱分析对样品的形貌和性质进行了表征.结果表明所制得YF3∶Er3+纳米纤维是纯正交相,带有空间群Pnma.YF3∶Er3+纳米纤维的直径大约为(89±11) nm且分布均匀.上转换发射光谱分析显示,在980 nm激发下,YF3∶Er3+纳米纤维在526、543和653 nm处发射出强的绿光和弱的红光,它们分别归属于Er3+的2 Hu/2→4I15/2、4 S3/2→4I15/2和4F9/2 →4 I15/2能级跃迁;在532 nm可见光激发下,YF3∶Er3+纳米纤维能够在1.52 μm处产生近红外发射.随着Er3+浓度的增加,YF3∶Er3+纳米纤维发光强度逐渐增大.由色坐标(CIE)图可知,YF3∶Er3+纳米纤维所发射的颜色位于色坐标的绿光区.此外,还提出了YF3∶Er3+纳米纤维可能的形成机理.
YF3 :Er^3+ nanofibers have been successfully fabricated via fluorination of the relevant Y2O3 :Er^3+ nanofibers which were obtained by calcining the electrospun PVP/[Y(NO3 )3 +Er(NO3 )3] composite nanofibers. The morphology and properties of the products were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersion spectrosco py (EDS) and fluorescence spectroscopy. The results showed that YF3 :Era+ nanofibers are pure orthorhombic phase with space group Pnma and the diameter of YF3 :Era+ nanofibers is (89 ± 11) nm. Upconversion emission spectrum analysis indicated that YF3 : Era+ nanofibers emit strong green and weak red light centered at 526, 543 and 653 nm, respectively, under the excitation of a 980 nm diode laser. The green emissions and the red emission are respectively attributed to ^2H11/2/^4 S3/2→4 I15/2 and 4 F9/2→4 I15/2 energy level transitions of the Era+ ions. The YF3 :Er3+ nanofibers emit nea~infrared emission centered at 1.52 μm under the excitation of 532 nm laser. Moreover, the emitting colors of the YFa :Era+ nanofibers are located in the green region in CIE chroma ticity coordinates diagram. The luminescent intensity of the YF3: Er3+ nanofibers increases remarkably with the increase of doping concentration of Era+ ions. Moreover, the possible formation mechanism of YF3: Er3+ nanofibers is also discussed.