Achieving high-sensitivity dual-mode optical thermometry via phonon-assisted cross-relaxation in a double-perovskite structured up-conversion phosphor

By adjusting the phonon energy of the host crystal (Ca 2+ /Sr 2+ /Ba 2+ ) LaLiTeO 6 :Yb 3+ , Tm 3+ phosphor, combined with the cross-relaxation phenomenon, a high-sensitivity thermometer for dual-mode temperature measurement was constructed.