ABSTRACT
The Sm3+ doped SrO-Nb2O5-Al2O3-Ga2O3-SiO2 glasses in this work were prepared using the conventional melt quenching method. The effects of Al2O3/Ga2O3 ratio on the structure and orange light emission properties were studied by XRD, Raman spectroscopy, spectrophotometer and J-O theory, respectively. With the increase of Al2O3 content, the absorption coefficient of the glass sample gradually increases, which might be attributed to an increase in non-bridged oxygen bonds caused by a change in the glass network structure. Under 403 nm excitation, the emission spectra show clear peaks at 602 nm and 649 nm, representing the 4G5/2 â 6H7/2, and 4G5/2 â 6H9/2 transitions, respectively. When the Al2O3/Ga2O3 ratio is 0.25, the sample luminescence intensity is the highest, and the emission cross section of A2 glass sample is 4.34 × 10-22 cm2. The CIE color coordinates, color purity, and color temperature values of all samples were determined, and they were all located in the orange-red light region. The experiments results reveal that the prepared silica-aluminum-gallium glasses has a potential application prospect in orange-red LEDs, solid state lasers and other fields.
ABSTRACT
Overcoming the restriction of the energy gap (700-800 cm-1) in Er3+-doped upconversion (UC) materials to achieve high detection accuracy is crucial for practical temperature detection applications. Herein, we design a feasible route based on the different thermal response behaviors of various hosts to enhance the SA value in a double perovskite NaLaMgWO6:Er,Mo system. The maximum SA value is 222.8 × 10-4@423 K in the NLMW:5%Er3+ host, and this can be promoted to 275.4 × 10-4 K-1@323 K in the NaLaMgWO6:Er,Mo system. The SR values decrease monotonously as the temperature rises, and this is due to the dependency of the SR values on the energy gap. A mechanism that is ascribed to the different thermal response behaviors of the various hosts is proposed, and this mechanism is further proved by investigating the temperature sensing properties of barium gadolinium zincate phosphors that possess the same thermal response behaviors. In addition, this study introduces the idea that a host with a high emission intensity for the 2H11/2 level and a lower emission intensity for the 4S3/2 level is highly suitable for temperature measurements. A thorough investigation of this system offers a strategy to acquire a high SA value and reveals the broad prospects of NaLaMgWO6:Er,Mo in the temperature detection field.
