【摘要】 采用Gd₂O₃,Yb₂O₃,Er₂O₃,HNO₃,CO（NH₂）₂和C₁₂H₂₅SO₄Na为实验原料,通过水热法合成了纳米Gd₂O₃:Yb³⁺,Er³⁺上转换发光粉体。通过X射线衍射（XRD）、差示扫描量热-热重分析（DSC-TGA）、傅里叶变换红外光谱（FT-IR）、透射电子显微镜（TEM）和上转换发射光谱（UCL）等对样品进行表征。研究结果表明:CO（NH₂）₂与Gd³⁺离子的摩尔比m影响前驱体的组成,当m=4时,前驱体是由晶态的Gd₂（CO₃）₃·xH₂O构成。该前驱体在空气气氛下800℃煅烧2h可获得单相的Gd₂O₃纳米粉体,粉体呈近球状,平均粒径约为30⁴0nm。上转换发光光谱表明,在980nm波长红外光激发下,Gd₂O₃:Yb³⁺,Er³⁺的主发射峰位于664nm波长处,呈红光发射,对应于Er³⁺的⁴F_9/2→⁴I_15/2跃迁。在波长为539nm和562nm附近呈现绿光发射,分别对应于Er³⁺的²H_11/2→⁴I_15/2和⁴S_3/2→⁴I_15/2跃迁。Er³⁺的猝灭浓度为1%。800℃煅烧合成的Gd₂O₃:Yb³⁺,Er³⁺纳米粉体的上转换发光机制为双光子模型,而1 200℃煅烧合成的Gd₂O₃:Yb³⁺,Er³⁺纳米粉体的上转换发光机制则为三光子模型。更多还原

【Abstract】 Gd₂O₃:Yb³⁺,Er³⁺nanophosphors were synthesized via a hydrothermal synthesis method with the starting materials of Gd₂O₃,Yb2 O3,Er₂O₃,HNO₃,CO（NH₂）₂ and C₁₂H₂₅SO₄ Na.The samples were characterized by X-ray diffraction（XRD）,differential scanning calorimetry thermogravimetric analysis（DSC-TGA）,fourier transform infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM）and up-conversion luminescence（UCL）spectra.The results show that the molar ratio of urea/Gd³⁺has a great influence on the phase structure of the precursor.The precursor is composed of Gd₂（CO₃）₃·xH₂O when the molar ratio of urea/Gd³⁺is 4,which can be transformed into near-spherical Gd₂O₃ powder with the average size of 30-40 nm by calcining at 800℃for 2 hin air.Under 980 nm infrared laser excitation,the strongest emission peak for the Gd₂O₃:Yb,Er nanophosphors is located at664 nm,which corresponds to the F_9/2→I_15/2 transition of Er ions.Moreover,the Gd₂O₃:Yb,Er nanophosphors also show green emission peaks at 539 nm and 562 nm,which are attributed to the transitions of H_11/2→I_15/2 and S_3/2→I_15/2 of Er ions,respectively.The quenching concentration of Er ions is 1%.The Gd₂O₃:Yb,Er nanophosphors show two-photo model emission mechanism at 800℃.When the temperature increases to 1 200℃,the emission mechanism changes into three-photo model.更多还原