Confining Excitation Energy in Er3+ -Sensitized Upconversion Nanocrystals through Tm3+ -Mediated Transient Energy Trapping

Qiushui Chen; Xiaoji Xie; Bolong Huang; Liangliang Liang; Sanyang Han; Zhigao Yi; Yu Wang; Ying Li; Dianyuan Fan; Ling Huang; Xiaogang Liu

doi:10.1002/anie.201703012

Confining Excitation Energy in Er³⁺ -Sensitized Upconversion Nanocrystals through Tm³⁺ -Mediated Transient Energy Trapping

Angew Chem Int Ed Engl. 2017 Jun 19;56(26):7605-7609. doi: 10.1002/anie.201703012. Epub 2017 May 24.

Authors

Qiushui Chen^{1

2}, Xiaoji Xie³, Bolong Huang⁴, Liangliang Liang², Sanyang Han², Zhigao Yi², Yu Wang¹, Ying Li¹, Dianyuan Fan¹, Ling Huang³, Xiaogang Liu²

Affiliations

¹ -NUS-SZU Collaborative Innovation Center for Optoelectronic, Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
² Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore.
³ Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergistic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China.
⁴ Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.

PMID: 28470867
DOI: 10.1002/anie.201703012

Abstract

A new class of lanthanide-doped upconversion nanoparticles are presented that are without Yb³⁺ or Nd³⁺ sensitizers in the host lattice. In erbium-enriched core-shell NaErF₄ :Tm (0.5 mol %)@NaYF₄ nanoparticles, a high degree of energy migration between Er³⁺ ions occurs to suppress the effect of concentration quenching upon surface coating. Unlike the conventional Yb³⁺ -Er³⁺ system, the Er³⁺ ion can serve as both the sensitizer and activator to enable an effective upconversion process. Importantly, an appropriate doping of Tm³⁺ has been demonstrated to further enhance upconversion luminescence through energy trapping. This endows the resultant nanoparticles with bright red (about 700-fold enhancement) and near-infrared luminescence that is achievable under multiple excitation wavelengths. This is a fundamental new pathway to mitigate the concentration quenching effect, thus offering a convenient method for red-emitting upconversion nanoprobes for biological applications.

Keywords: Er3+ sensitizers; energy migration; optical imaging; transient energy trapping; upconversion nanocrystals.

Publication types

Research Support, Non-U.S. Gov't