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Due to the excellent infrared transparency, low phonon energy, and high rare‐earth solubility, germanate laser glass has attracted much attention in mid‐infrared fiber lasers for potential coherent laser radar systems, optical detection, remote sensing, and laser surgery. However, radiation‐induce darkening often occurs in fiber lasers that operate in radiation environment. Here, we report a useful strategy to improve the radiation resistance by adding multivalence Bi ions and discuss its radiation resistance mechanism. In order to study the effect of valence states on the radiation resistance of barium gallo‐germanate glass, we adjust the valence states of Bi ions by heat treatment, the potential mechanism of which is discussed in detail based on the absorption, photoluminescence (PL), and Raman spectra. The absorption, electron paramagnetic resonance, and photoluminescence spectra have proved the interconversion of Bi ions between low and high valence, which inhibits the formation of Ge‐related electron center (GEC) and non‐bridging oxygen hole center defects in the irradiation process. In addition, the Bi3+ content increased by heat treatment is beneficial to serve as electron‐trapping centers in γ‐ray irradiation, thus further reducing the formation of GEC. This study provides a simple method to achieve Bi valence regulation, so as to improve the radiation resistance.

Though widely applied in light-emitting diode (LED) lighting and X-ray detection, respectively, rare-earth ions doped phosphor and scintillating single crystals still face many challenges in practicalities, like aging of package material and difficulty to construct tiny array structure. Using phosphate glass as the host is quite beneficial for solving these problems while enabling distinguished luminescence. Therefore, Eu 3+ and Tb 3+ doped phosphate glasses which, respectively, show strong red/green emissions are researched. Superior thermal stabilities (78.69% and 89.35% emission intensities remain at 150 °C) and high internal quantum efficiencies (87.3% and 68.6%) are found to guarantee the excellent photoluminescence performances. The brilliant X-ray excited luminescence properties are demonstrated by general 19.49% and 34.74% integrated emission intensities of that of commercial Bi 4 Ge 3 O 12 single crystal scintillator with the change of X-ray power. Meanwhile, Tb 3+ doped scintillating fiber is drawn. Finally, excited by 380 nm LED, color manipulation and white light generation are achieved in LEDs with a structure of stacked emitting layers (mainly Eu 3+ and Tb 3+ doped phosphate glasses). Many of the as-constructed white LED's performance parameters are much better than the commercial white LED. These results show that Eu 3+ and Tb 3+ doped phosphate glasses possess promising potential in LED lighting and X-ray detections.

Compared with conventional white light emitting diodes, white lasers are highly desired for application in visible light communication due to their higher modulation bandwidth and light output power. However, the...

An in-depth understanding of the influence mechanism of the nonprecious metal Fe promoter on CO2 methanation is of great significance to the optimal design of high-efficiency CO2 methanation catalysts. In this research, CeO2 and Al2O3-supported Ni-based catalysts were prepared and evaluated for the CO2 methanation reaction. Interestingly, it was found that the addition of Fe into the CeO2-supported Ni catalyst lowered the CO2 methanation performance, while it greatly enhanced the performance of the Al2O3-supported Ni catalyst. A variety of factors over Fe-modified catalysts were explored, in which surface basicity along with oxygen vacancies could contribute to the adjustment of the CO2 methanation performance.

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