Upconversion luminescence through dynamically regulating the depletion of Ho3+: 5I6 level for speed sensing

Di Wu; Tao Pang; Ying Ji; Peizhen Qiu; Zixun Zhou

doi:10.1016/j.saa.2024.124318

Upconversion luminescence through dynamically regulating the depletion of Ho³⁺: ⁵I₆ level for speed sensing

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Apr 20:316:124318. doi: 10.1016/j.saa.2024.124318. Online ahead of print.

Authors

Di Wu¹, Tao Pang², Ying Ji¹, Peizhen Qiu¹, Zixun Zhou¹

Affiliations

¹ Huzhou Key Laboratory of Materials for Energy Conversion and Storage, College of Science, Huzhou University, Huzhou 313000, China.
² Huzhou Key Laboratory of Materials for Energy Conversion and Storage, College of Science, Huzhou University, Huzhou 313000, China. Electronic address: tpang@126.com.

PMID: 38663136
DOI: 10.1016/j.saa.2024.124318

Abstract

In this work, a strategy for dynamically adjusting the upconversion luminescence (UCL) color of NaGdF₄:Yb³⁺/Ho³⁺/Ce³⁺/Sc³⁺ is reported based on a phosphor wheel. It has been demonstrated that the rotation-dependent UCL mainly originated from the regulation of depletion mode for the Ho³⁺: ⁵I₆ level. Due to the dominant linear decay, a high-pure red UCL is observed under the steady-state excitation. However, as the proportion of the steady-state excitation decreases, the green-red emission intensity ratio gradually increases, followed by the color conversion from red to green. An approximate physical model is proposed to understand the dependence of I_G/I_R on rotation speed. We not only report a UCL material that shows potential application in velocity sensing but also provide new insights into wheel-based dynamic UCL regulation.

Keywords: Color tuning; Ho(3+); Speed sensing; Upconversion luminescence.