Volf Jakub, Vařák Petr, Buryi Maksym, Kormunda Martin, Nekvindová Pavla
Department of Inorganic Chemistry, University of Chemistry and Technology, Technická 5, 166 28 Prague, Czech Republic.
Institute of Plasma Physics, Czech Academy of Sciences, U Slovanky 2525/1a, 182 00 Prague, Czech Republic.
Materials (Basel). 2025 Apr 25;18(9):1948. doi: 10.3390/ma18091948.
Non-hygroscopic borosilicate glasses containing Ce and Mn ions were prepared using the conventional melt-quenching method. The electrochemical equilibrium of the Ce and Mn oxidation states has a significant effect on the energy levels and luminescence of both elements. Consequently, the oxidation states in the glasses were analyzed using a combination of XPS, EPR, and absorption spectroscopy. The oxidation-reduction equilibrium was altered by systematically changing three factors: the Mn concentration, the presence or absence of SnO as a reducing agent, and the optical basicity of the glass. Upon excitation with light with a wavelength of 320 nm, the prepared glasses exhibited a blue luminescence band in the region of 350-450 nm, corresponding to the Ce ion, and a broad, weak red luminescence emission in the region of 540-640 nm, corresponding to Mn ions. To obtain a high luminescence intensity for both bands, it was necessary to reduce the MnO content below 1 mol.%. Furthermore, doping the glasses with Sn ions helped to maintain both cerium and manganese in low oxidation states, resulting in measurable luminescence in both observed bands. These low oxidation states of Ce and Mn can also be achieved by reducing the optical basicity of the glass through the addition of MgO. The general relationships obtained could potentially be applied in the production of light-emitting diodes or field-emission displays that utilize energy transfer.
采用传统的熔体淬火法制备了含有铈（Ce）和锰（Mn）离子的非吸湿性硼硅酸盐玻璃。Ce和Mn氧化态的电化学平衡对这两种元素的能级和发光有显著影响。因此，结合X射线光电子能谱（XPS）、电子顺磁共振（EPR）和吸收光谱对玻璃中的氧化态进行了分析。通过系统地改变三个因素来改变氧化还原平衡：Mn浓度、作为还原剂的SnO的有无以及玻璃的光学碱度。用波长为320 nm的光激发时，制备的玻璃在350 - 450 nm区域表现出对应于Ce离子的蓝色发光带，在540 - 640 nm区域表现出对应于Mn离子的宽而弱的红色发光发射。为了使两个波段都获得高发光强度，有必要将MnO含量降低到1 mol.%以下。此外，用Sn离子掺杂玻璃有助于将铈和锰都保持在低氧化态，从而在两个观察到的波段都产生可测量的发光。通过添加MgO降低玻璃的光学碱度也可以实现Ce和Mn的这些低氧化态。所得到的一般关系可能会应用于利用能量转移的发光二极管或场发射显示器的生产中。
