LAUSR

The Er3+/Yb3+-codoped Y2Mo4O15 microparticles, which possessed admirable optical thermometric and upconversion (UC) emission behaviors, were synthesized through the traditional sintering technology of the sol–gel route. Under near-infrared (NIR) light excitation, the obtained compounds showed the featured green and red UC emissions of Er3+ ions. The most intense luminescent intensity was detected when the Yb3+ ion content was 40 mol %. Through studying the temperature-dependent UC emission intensity ratio of the monitored green emissions, the optical thermometric properties of the resultant microparticles were investigated. The maximum sensor sensitivity of the studied microparticles with optimum doping concentration was approximately 0.00846 K–1. Moreover, the achieved maximum sensor sensitivity was independent of the dopant content that was identical with the theoretical analysis by taking advantage of the Judd–Ofelt theory. Furthermore, a significant increment in the compounds’ temperature was achieved...