[en] To date, the white light lanthanide upconvertion consisting of RGB components usually originated from more than one type of emitter. Alternatively, Pr³⁺ is a fascinating lanthanide ion featuring multiple visible emission bands, including RGB components that in principle enable Pr³⁺ to emit white light. In this paper, we report, for the first time to our knowledge, white light upconversion through dual sensitization routes in Nd/Yb/Pr triply doped NaYF₄ microrods upon 800 nm excitation. It is found that the dual sensitization is more efficient than single sensitization for Pr³⁺ upconversion. In addition, the temperature sensing behaviors of the proposed triply doped microrods are comparatively investigated using different emission bands. This work presents a novel white light emitting material upon 800 nm excitation, and further demonstrates the feasibility of multichannel thermometry using the proposed material.

[en] Various concentrations of Ho³⁺ and Nd³⁺ codoped NaYF₄ nanorods were successfully synthesized. On the basis of the upconversion spectra under 808 nm excitation, the luminescence mechanisms were discussed in detail. The ratio of red to green intensity evidently increases with increasing the Nd³⁺ content due to the stronger interactions between Ho³⁺ and Nd³⁺, which enhance the red emission and suppress the green one. In addition, we found that the red emission is more sensitive to the ambient temperature as compared to the green one, thus validating the thermal sensing by applying the ratiometric method by using these two emission bands. Relatively high sensing sensitivity of 0.9% was obtained, evidencing the great potential of the presented optical thermometer.