Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (3): 244-248.DOI: 10.6023/A21120618 Previous Articles     Next Articles

Special Issue: 中国科学院青年创新促进会合辑



胡晓柯a,b, 商晓颖b, 黄萍a,b,*(), 郑伟a,b, 陈学元a,b,*()   

  1. a 福建师范大学 化学与材料学院 福州 350007
    b 中国科学院福建物质结构研究所 中国科学院功能纳米结构设计与组装重点实验室 福建省纳米材料重点实验室 结构化学国家重点实验室 福州 350002
  • 投稿日期:2021-12-31 发布日期:2022-02-17
  • 通讯作者: 黄萍, 陈学元
  • 作者简介:
  • 基金资助:
    中国科学院青年创新促进会专项(2020305); 国家自然科学基金(12174391); 国家自然科学基金(U1805252); 国家自然科学基金(21875250); 国家自然科学基金(12074379); 国家自然科学基金(12104456); 福建省自然科学基金对外合作项目(2020I0037)

Polarized Upconversion Luminescence from a Single NaYF4:Yb3+/Er3+ Microrod for Orientation Tracking

Xiaoke Hua,b, Xiaoying Shangb, Ping Huanga,b(), Wei Zhenga,b, Xueyuan Chena,b()   

  1. a College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007
    b State Key Laboratory of Structural Chemistry, Fujian Key Laboratory of Nanomaterials, CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences, Fuzhou 350002
  • Received:2021-12-31 Published:2022-02-17
  • Contact: Ping Huang, Xueyuan Chen
  • About author:
    Dedicated to the 10th anniversary of the Youth Innovation Promotion Association, CAS.
  • Supported by:
    Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020305); National Natural Science Foundation of China(12174391); National Natural Science Foundation of China(U1805252); National Natural Science Foundation of China(21875250); National Natural Science Foundation of China(12074379); National Natural Science Foundation of China(12104456); Natural Science Foundation of Fujian Province(2020I0037)

Polarized upconversion luminescence (UCL) of lanthanide (Ln3+)-doped micro/nano-crystals has shown great promise in areas such as single-particle tracking and biomedicine. The polarized UCL of Ln3+ ions is governed by their localized electronic structures and excited-state dynamics. In this work, β-NaYF4:Yb3+/Er3+ microrods with controllable morphologies and sizes were synthesized through a solvothermal method. Based on the customized confocal laser microscopic system, the polarized UCL of a single β-NaYF4:Yb3+/Er3+ microrod was systematically investigated. The emission polarization was probed by placing a half-wave plate coupled with a polarizer in front of the detector. As such, the polarized UCL spectra of a single NaYF4:Yb3+/Er3+ microrod can be recorded by rotating the half-wave plate under 980-nm excitation. It was observed that the UCL intensity of the microrod exhibited a periodic variation with the emission polarization angle tuning from 0° to 360°, indicating polarization anisotropy of the microrod. Specifically, different crystal-field (CF) transition lines originating from two identical multiplets of Er3+ displayed drastically distinct polarization dependence. This results in a higher degree of polarization (DOP) of the UCL intensity for a certain CF transition of Er3+ in comparison with that of the integrated UCL intensity of the multiplet. Polar plots of the UCL intensities for the CF transitions of Er3+ as a function of polarization angle could provide a qualitative vision of the DOP, with a narrower “neck” indicative of a larger DOP. Moreover, the polar plots of a certain CF transition of Er3+ showed a consistent orientation with the corresponding NaYF4:Yb3+/ Er3+ microrod and rotated with the rotating of the single microrod. Therefore, by utilizing the polar plots of the highly-polarized CF transition lines of Er3+, the spatial orientations of the microrod could be monitored, thus revealing the great potential of NaYF4:Yb3+/Er3+ microrods as sensitive anisotropic UCL probes for single-particle tracking.

Key words: rare earth, upconversion luminescence, polarization anisotropy, single particle, crystal-field transition