Strong luminescence intensity and high temperature sensitivity of Er3+-doped KYb(MoO4)2 phosphors optimized by codoping trivalent ions

Rare earth doped upconversion luminescent materials have the advantages of low toxicity, high chemical stability, excellent photostability, narrow emission band, and long luminescent life, but their low fluorescence quantum efficiency restricts their practical application in the field of temperature sensing. In this paper, Er3+ doped KYb(MoO4)2 (KYM) phosphors were synthesized by a temperature solid state reaction method. When the doped concentration is 5 mol%, the luminescence intensity get its strongest value. On this basis, 2 mol% trivalent ions Gd3+, La3+ and Y3+ (R3+) were doped respectively, and the luminescence intensity increased by about 2 times. By the fluorescence intensity ratio technique, the KYM:5Er phosphor has the maximum absolute temperature sensitivity of 0.0106 K-1. By codoping 2 mol% Gd3+ in KYM:5Er, the upper limit of temperature measurement increased from 513 K to 663 K, which shows that Er3+-doped and Er3+/R3+-codoped KYM have the potential as temperature sensors.