Highly-sensitive optical thermometer developed based on an intervalence charge transfer mashup

Zhihua Liu; Yunzhong Zhu; Rui Hao; Shaopeng Lin; Decai Ma; Biao Wang

doi:10.1016/j.talanta.2024.126054

Highly-sensitive optical thermometer developed based on an intervalence charge transfer mashup

Talanta. 2024 Jul 1:274:126054. doi: 10.1016/j.talanta.2024.126054. Epub 2024 Apr 4.

Authors

Zhihua Liu¹, Yunzhong Zhu², Rui Hao³, Shaopeng Lin¹, Decai Ma¹, Biao Wang⁴

Affiliations

¹ Sino French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai, 519082, China.
² Sino French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai, 519082, China. Electronic address: zhuyzh7@mail.sysu.edu.cn.
³ School of Physics, Sun Yat-Sen University, Guangzhou, 510275, China.
⁴ Sino French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai, 519082, China; School of Physics, Sun Yat-Sen University, Guangzhou, 510275, China.

PMID: 38599122
DOI: 10.1016/j.talanta.2024.126054

Abstract

Optical thermometers based on lanthanide thermal-coupled levels have attracted great attention owing to its fundamental importance in the fields of public health, biology, and integrated circuit. However, the inherent structural properties (shielded effect on 4f configurations, intense non-radiation relaxation) strictly suppress the sensing performance, limiting the relative temperature sensitivity (S_R). To circumvent these limitations, we propose an intervalence charge transfer mashup strategy by inducing d⁰ electron configured transition metals. Specifically, transition metals Ta⁵⁺ is incorporated in Tm³⁺/Eu³⁺:LiNbO₃, which improves the S_R from 5.30 to 11.16% K^-1. The validity of this component-modulation behavior is observed on other oxide crystals (NaY(Mo_1-zW_zO₄)₂) as well. Furthermore, the observed regulation is well explained by DFT calculation that indicates the d-orbit component at valence band minimum remains the core factor governing the electron transfer process. We successfully relate the S_R to the band structure of luminescence carrier, offering a novel perspective for the collocation design of lanthanide configurations.

Keywords: Intervalence charge transfer mashup; Lanthanides; Lithium niobate; Optical thermometer; Thermal-coupled relationship.