Abstract:
In the present study, the synthesis of BaSrSiO4 co-doped Yb3+ and Nd3+ nanophosphors (NPs) was successfully achieved through the conventional sol-gel method, as confirmed by X-ray diffraction and SEM analysis, verifying the formation of pure NPs. The FTIR and Raman spectra analysis confirm the formation of silicates, as different modes and vibrations of Si-O and Si-O-Si were seen at 800-1000 cm-1. The energy transfer (ET) mechanism between Nd3+ and Yb3+ ions was seen as the emission spectra showed a rise in intensity of one over another. PLE emission spectra showed transitions at 2F7/2-2F5/2 for Yb3+ and from 4F3/2 to (4I9/2, 4I11/2, and 4I13/2) for Nd3+ when excited at 785 nm. All the samples record low activation energy, which shows that the rate of reaction will be higher in all the samples, and it will be highest for 1 mol% Nd3+ and 1 mol% Yb3+. An increasing value of τ was seen with increasing Yb3+ concentration, which confirms the increase in the population of trap centers. The positron annihilation lifetime (PAL) curve showed that 1 mol% Yb3+ and 2 mol Nd3+ have single vacancies or shallower positron traps, whereas 3 mol% Yb3+ and 2 mol% Nd3+ have larger defects like surface oxygen vacancy clusters. The other two samples have balance vacancies, which makes them best for thermometry applications. The fluorescence intensity ratio (FIR) was calculated to get sensitivity for thermometry application. 2.13% K-1 sensitivity achieved at 303-333 K temperature.
摘要:
在本研究中,通过常规溶胶-凝胶法成功合成了BaSrSiO4共掺杂的Yb3+和Nd3+纳米荧光粉(NPs),X射线衍射和扫描电镜分析证实,验证纯NP的形成。FTIR和拉曼光谱分析证实了硅酸盐的形成,在800-1000cm-1处看到Si-O和Si-O-Si的不同模式和振动。可见Nd3和Yb3离子之间的能量转移(ET)机制,因为发射光谱显示出一个比另一个的强度上升。当在785nm激发时,PLE发射光谱显示Yb3的2F7/2-2F5/2跃迁,Nd3的4F3/2跃迁至(4I9/2,4I11/2和4I13/2)。所有样品的活化能都很低,这表明所有样品的反应速率都会更高,1摩尔%Nd3+和1摩尔%Yb3+最高。τ的值随着Yb3+浓度的增加而增加,这证实了陷阱中心人口的增加。正电子an灭寿命(PAL)曲线表明,1mol%Yb3和2molNd3具有单个空位或较浅的正电子陷阱,而3摩尔%Yb3+和2摩尔%Nd3+具有较大的缺陷,如表面氧空位簇。另外两个样本有余额空缺,这使得它们最适合测温应用。计算荧光强度比(FIR)以获得测温应用的灵敏度。在303-333K温度下达到2.13%K-1灵敏度。