Upconversion luminescence and temperature sensing properties of Er3+/Yb3+/Gd3+ co-doped YNbO4 phosphors

Owing to the great role and application potential of upconversion luminescent materials in the field of temperature sensing, it is very essential to develop new rare-earth materials with excellent upconversion luminescence (UCL) and temperature sensing properties. In this study, an Er3+/Yb3+/Gd3+ co-doped YNbO4 as a UCL material was synthesized. In this system, Er is used as the luminescence centre; Yb is used as the sensitizer, and Gd can effectively adjust the crystal field of the matrix material and improve the UCL performance. In addition, the composition and intrinsic luminescence mechanism of the materials are studied in detail. It can be seen that the UCL intensity was strengthened for Er3+/Yb3+/Gd3+ co-doped YNbO4 compared to Er3+/Yb3+ co-doped YNbO4. The results show that Gd3+ can effectively improve the UCL intensity of Er3+/Yb3+-doped YNbO4 samples. Using fluorescence intensity ratio technology, we obtained the temperature sensing performance of the material, which has the highest sensitivity at 493 K (0.0033 K−1). This suggests that the material has great application potential in the fields of UCL and temperature sensing.