Molten salts synthesized L‐Ta2O5:Er3+/Yb3+ with superior pure green upconversion luminescence

Abstract

AbstractL‐Ta2O5:Er3+/Yb3+ upconversion phosphors were synthesized by employing the molten salts method with B2O3 as solvent. The optimal doping concentrations of Er3+ and Yb3+ are 0.2 and 2.5 mol%, respectively. The green upconversion luminescence (UCL) integral intensity of the acid‐pickling sample reached 40% of β‐NaYF4:Er3+/Yb3+ under 980 nm laser excitation. Er3+/Yb3+ may take the sites of Ta5+ and insert into the interlayers of L‐Ta2O5. Using the luminescence intensity ratio (LIR) technique, the relative temperature sensitivity was obtained to be 0.95 %K−1 at 303 K. L‐Ta2O5:Er3+/Yb3+ with outstanding pure green UCL intensity and high‐temperature sensitivity can be applied to luminescence display and temperature sensing.