硼酸盐玻璃中Eu掺杂对Ag纳米颗粒的析出机制及其发光性质研究

摘要

采用高温熔融法制备了Eu-Ag共掺的硼酸盐玻璃，利用吸收光谱和发射光谱等研究了玻璃中网络形成体B2 O3含量变化和Eu离子共掺对于Ag在基质中赋存状态的影响。在Eu-Ag 共掺玻璃的吸收光谱中发现，随着B2 O3含量的增加，Ag纳米颗粒在410 nm附近的宽带吸收强度逐渐下降；玻璃在340 nm光源激发下，位于350～600 nm的蓝绿光区出现一个Ag分子团簇的宽带发光，且其发光强度随B2 O3含量的增加逐渐增强。在Eu或Ag单掺的玻璃中可分别观测到微弱的Eu3＋或Ag分子团簇的本征发射，而Eu-Ag共掺样品中Eu3＋和Ag分子团簇的发光都得到了显著的增强。并且Eu离子浓度的增加促进了Ag纳米颗粒在410 nm附近的宽带吸收。对Eu离子的添加促进 Ag 纳米颗粒析出的机理进行了讨论。同时，由于 Eu3＋的5 D0→7 FJ 的电子跃迁发射为橙红光，Ag纳米团簇可发射蓝绿光甚至黄光，因此通过玻璃结构的调控和 Eu离子掺杂浓度的调节可以实现玻璃的白光发射，这有望成为潜在的白光LED用玻璃照明材料。%Eu-Ag co-doped borate glasses were prepared by the high temperature solid method in the present work.Absorption and emission spectra were employed to investigate the precipitation of Ag nanoparticles,which is influenced by the network form B2 O3 and the co-doped Eu ions.It was found in the absorption spectra of Eu-Ag co-doped sample that a broad band centered at about 410 nm emerged and their intensity decreased with the increase in the B2 O3 concentration.Meanwhile,under the excitation of 340 nm,a broad emission band was observed in the wavelength range of 350~600 nm,which belongs to the blue-green light of Ag aggregates.The intensity of the Ag aggregates presented an increasing tendency with the increase in the B2 O3 contents. The weak characteristic emission of Ag aggregates and Eu3+ was observed respectively in their singly doped samples.It is con-cluded that both their emissions get significant enhancement when Eu ions and Ag ions are used for co-doping the sample.In ad-dition,the increased absorption of Ag nanoparticles was detected with the increase in the Eu ions concentration.Herein,the mechanism behind Eu3+ contribution to the precipitation of Ag nanoparticles is discussed in detail.The luminescence properties of borate glasses can be controlled by the microstructure of the borate glasses.Therefore,the white emission can be realized by the adjustment of glass structure and Eu ions concentration,owing to the red light from Eu3+:5D0→7FJ electronic transition and the blue-green light form the broad emission of Ag aggregates.The borate glasses are expected to be the candidates for the light-emission diode (LED)luminescent materials.