Sensitivity improvement induced by thermal response behavior for temperature sensing applications.

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.