Enhancement on concentration quenching threshold and upconversion luminescence of β-NaYF_4:Er~(3+)/Yb~(3+) codoping with Li~+ ions

摘要

The application of upconversion (UC) materials, especially in solar cells, is still constrained because of their lower UC efficiency. In this work, co-doped Li~+ was used to enhance the UC luminescence of β-NaYF_4:Er~(3+)/Yb~(3+) microcrystals. The influence of Li~+ on the quenching concentration of Er~(3+) was investigated. The UC emission intensity was signiflcantiy improved by introducing different concentrations of Li~+ ions. After 4 mol% Li~+ doping, the quenching concentration of Er~(3+) increases from 2% to 4 mol%. Meanwhile, the green and red emission is enhanced 2 and 3.3 times, respectively. The results indicate that both the emission intensity and the quenching concentration can be increased by Li~+ doping.