None‐rare‐earth activated Ca14Al10Zn6O35:Bi3+,Mn4+ phosphor involving dual luminescent centers for temperature sensing

Abstract

AbstractWe proposed a new strategy for utilizing rare‐earth–free‐activated self‐referencing optical material with dual activators for temperature sensing, which was synthesized by conventional high‐temperature solid‐state method and was scarcely reported. Originating from the different thermal responses of Mn4+ and Bi3+ ions, a Mn4+/Bi3+‐based dual‐emitting fluorescence intensity ratio (FIR) as dual‐modal temperature signal for temperature sensing has been corroborated as a promising temperature sensing method. Due to the outstanding thermal resistance of activator Mn4+ (anti‐Stokes) benefiting from the unique 3dn electronic configurations and strong field strength of host, together with the energy transfer from Bi3+ to Mn4+ ions and excellent thermal quenching of Bi3+, this temperature‐sensitive phosphor displayed both an extensive detection temperature region ranging from 303 to 563 K and excellent absolute and relative sensitivity of 0.0147 K−1 and 1.21% K−1 respectively, both of which are higher than some foregoing reported optical materials. Furthermore, two well‐separated emission peaks at blue and red regions enabled an excellent signal discriminability and accurate temperature detection under the single‐wavelength excitation of 340 nm. In addition, freedom from rare‐earth ions contributed its possibility to be mass‐produced for meeting the needs of economic rationality, nontoxic and convenient synthesis. It is anticipated that this preliminary study would arouse peoples’ attention on exploring more novel dual activator‐based optical thermometric materials in absence of rare‐earth ions.