Phase transformation and morphology tuning of β-NaYF4:Yb3+,Er3+ nanocrystals through K+ ions codoping<xref ref-type="fn" rid="cpb141850fn1">*</xref>

Phase transformation and morphology tuning of β-NaYF₄:Yb³⁺,Er³⁺ nanocrystals through K⁺ ions codoping*

Liang Zhi-Qin^a),^b), Zhao Su-Ling^a),^b)†, Cui Yue^a),^b), Tian Li-Jiao^a),^b), Zhang Jun-Jie^a),^b), Xu Zheng^a),^b)

(a) UC emission spectra of the samples with different concentrations of K⁺ ions. All of them are measured under the same conditions. (b) Red-to green (R/G) emission ratios as a function of the content of K⁺ ions.