中国稀土学会2017学术年会

2017-05-11 00:00:01

中国北京

A strategy to improve the sensitivity of luminescent thermometer is elaborated via energy transfer between Er~(3+) and Mn~(2+) ions.The Yb~(3+)/Er~(3+) and Yb~(3+)/Er~(3+)/Mn~(3+) co-doped Na Lu F4 upconversion phosphors are prepared.Notably,introducing Mn~(2+) for NaLuF_4:Yb~(3+)/Er~(3+) phosphor rusults in enhancing the red to green intensity ratio,which acts as a bridge for energy transfer between ~4S_(3/2) and 4F9/2 levels of Er~(3+).The temperature sensing behaviors of two phosphors are ivestigated in temperature 295-595 K range using a ratiometric technique under 980 nm excitation.Based on thermally(2H11/2 and 4S3/2) and non-thermally(~4F_(9/2) and ~4S_(3/2)) coupled levels of Er~(3+),the effect of this energy transfer is discussed for the performance of temperature sensing.The temperature dependent spectra demonstrate that the addition of Mn~(2+) lead to improve the sensitivity for temperature detection based on non-thermally coupled levels.Furthermore,the sensitivity of Na Lu F4:Yb~(3+)/Er~(3+) doping with Mn~(2+) ions based on non-thermally coupled levels is much higher than that without Mn~(2+) ions based on both thermally and non-thermally coupled levels in the temperature 295-525 K range.The maximum sensitivity is 10.99×10~(-3) K~(-1) at 295 K for Na Lu F4:Yb~(3+)/Er~(3+)/Mn~(3+) phosphor.These results indicate that introducing Mn~(2+) ions in NaLuF_4:Yb~(3+)/Er~(3+) phosphor is an effective method for enhancing sensitivity in temperature 295-525 K range.