Tunable upconversion luminescence and enhanced temperature sensitive properties from Bi2Ti2O7:Yb3+/Er3+ nanofibers

Unraveling the morphology of the sensing material is of paramount in realizing the better sensitivity. For this purpose, the Bi2Ti2O7:Yb3+/Er3+ nanofibers (0:1, 4:1, 8:1, 15:1, 20:1) and nanoparticles were synthesized via an electrospinning and sol–gel route, respectively. Subsequently, the temperature sensing properties based on the fluorescence intensity ration were studied within Bi2Ti2O7:Yb3+/Er3+ nanofibers and particles in the range of 298–538 K. The maximum relative sensitivity value was 1.53% at 298 K for Bi2Ti2O7:Yb3+/Er3+ (4:1) nanofibers. As was expected, Bi2Ti2O7:Yb3+/Er3+ nanofibers demonstrated an enhanced temperature sensitivity than that of the individual nanoparticles, exhibiting the champion values among all the reported Yb–Er pairs. To exploit the potential for practical application, the Bi2Ti2O7:Yb3+/Er3+ nanofibers were utilized to measure the surface temperature of a heating object. An improved surface temperature resolution was realized compare with the infrared thermal camera. All the presented results confirmed that the novel upconversion Bi2Ti2O7:Yb3+/Er3+ nanofibers could be an outstanding candidate for temperature sensors. Our work has proven to be a reliable alternative for exploring contactless temperature sensing at a higher resolution.