Intense near-infrared emission, upconversion processes and temperature sensing properties of Tm3+ and Yb3+ co-doped double perovskite Gd2ZnTiO6 phosphors

Abstract

Research on near-infrared (NIR) emission of Tm3+ and Yb3+ co-doped upconversion (UC) materials has accepted many interests owing to delightful features for frontier applications. In this work, we focus on the preparation of pure NIR emission and the improvement of absolute sensitivity (SA) on temperature in Tm3+ and Yb3+ co-doped novel double perovskite Gd2ZnTiO6 (GZT) phosphors. Upon 980 nm excitation, these phosphors perform dramatical NIR emissions, and the integral intensity percentage of NIR emission versus total visible emissions reaches up to 99.88%. A high SA value with 1.7351 K−1 at 473 K for the I801/I650 is obtained via introducing excellent NIR emission. Besides, the SA value of non-thermally coupled levels is higher than that of thermally coupled levels. These results suggest that this kind of UC material may be a candidate for NIR imaging and temperature detection applications.