Phonon‐Assisted Negative Thermal Quenching in a One‐Photon Up‐Conversion Phosphor for Thermometry

Abstract Thermal disturbance deteriorates the radiative transitions of up‐conversion phosphor, leading to decreased emission intensity at high operation temperatures. In this work, a thermal‐favored Yb 3+ /Nd co‐doped KGaGeO 4 phosphor with negative thermal quenching behavior is explored. The as‐developed performs one‐photon anti‐Stokes and exhibits remarkable enhancement for rise ambient temperature reaching 653 K. It demonstrated that fascinating procedure attributed enhanced energy transfer from corresponding sensitizers activators by phonon assistance. Moreover, microscopic dynamical process assistance annihilation revealed introducing Er ions as probe. These results not only shed light on phonon‐assisted strategy build highly efficient system but also open prospects constructing phonon‐favored nonthermally coupled emissions realize luminescence thermometry their distinct responsivity.