Broad combined orange-red emissions from Eu^2+- and Eu^3+-doped low-silica calcium aluminosilicate glass

Abstract

In this paper, a broad combined orange-red emission from Eu²⁺- and Eu³⁺-doped low-silica calcium aluminosilicate (LSCAS) glass is reported. Spectroscopic results demonstrate that it is possible to tune the emission wavelength by changing the excitation wavelength in the UV-Vis region. The color coordinates for the emission spectra were calculated, and using the Commission Internationale de l'Éclairage 1931 and 1976 chromatic diagrams, it is possible to note that they are dependent on the excitation wavelength. In addition, the (u', v') color coordinates for the investigated LSCAS samples are close to the Planckian spectrum in the cold region between 2000 and 2600K. Our results show that the Eu:LSCAS system can be used in a white light phosphor when mixed in aggregate with phosphors using green-yellow luminescent ions.

Emission tunability and local environment in europium-doped OH−-free calcium aluminosilicate glasses for artificial lighting applications

“…This behavior was in agreement with the ESR data. The coexistence of Eu 2þ and Eu 3þ in OH À -free LSCAS glass has been reported previously [10,11,29]. In an earlier study [29], overlapping of the emission lines between 570 and 750 nm was observed, attributed to the 5 D 0 / 7 F J (J 0, 1, 2, 3, and 4) transitions of the Eu 3þ ion.…”

“…The observed behavior was like a mirror, compared to the ESR intensity. Although the use of 350 nm does not directly excite Eu 3þ , energy transfer from Eu 2þ to Eu 3þ by reabsorption is possible, due to the overlap among Eu 2þ absorption bands and Eu 3þ absorption lines, as reported recently [10]. Wang et al [30] suggested that a decrease in the Eu 2þ emission intensity can result from an increase in the number of non-bridging oxygens (NBOs), caused by a greater number of negative charges in the glass network.…”

“…These studies employed systems doped with Ce [7,12], Eu [10], and CeeEu [11]. The results revealed a significant influence of melting under a vacuum atmosphere on the production of glasses with ions in reduced oxidation states and with minimal presence of OH À in their structures.…”

White Cathodoluminescence Emission from Eu‐Doped SiAlON Thin Films

“…It is noteworthy that the quite broad and white emission spectrum obtained for the SiAlON:Eu films has been achieved with an almost uniform composition throughout the film (see Figure ). In contrast, other authors in order to achieve a similar white response have had to overlap the contribution of films or powders with different compositions, each with a narrow emission in order to obtain similar chromatic coordinates . Therefore these results are relevant because they show that amorphous SiAlON films with a nanostructured Eu 2+ ‐doping might be used for solid state white‐light emitters such as field emission flat lamps and displays.…”

Synthesis and luminescent properties of Eu3+/Eu2+ co-doped calcium aluminosilicate glass–ceramics

“…Recently, the potentiality of low silica calcium aluminosilicate (LSCAS) glass to generate smart lighting was studied in Eu 3 þ /Eu 2 þ doped samples [14] and the results showed that Eu 2 þ yelloworange emission can be combined with Eu 3 þ red emission for white light phosphor. Over the past, we have studied Eu 2 þ doped calcium aluminosilicate (CAS) glass [15] and showed that this material is a promising phosphor toward the development of a smart lighting.…”