Optimizing optical thermometry with tri-doped Ba2GdV3O11 phosphors: Ratiometric and fluorescence lifetime analysis

Abstract

Optical sensor technology has undergone a transformative evolution with the advent of fluorescence ratio techniques (FIR) and fluorescence lifetime (FL) strategies, revolutionizing precision, performance, and reliability. This study delves into the synthesis of Ba2GdV3O11 phosphors doped with Ho3+/Nd3+, Er3+, and Yb3+, employing the sol-gel method for upconverting material fabrication. A thorough investigation into the structural, morphological, and optical properties of the synthesized phosphors is conducted. Excitation at 980 nm unveils upconversion (UC) emissions across green and red spectra. The intensities of the observed emission bands for Ho3+, Nd3+, and Er3+ demonstrate significant sensitivity to fluctuations in temperature. Temperature sensing relies on the 4S3/2 and 2H11/2 upconversion emissions bands, in addition to the emission lifetimes at 4S3/2. Enhanced thermal sensitivity values are attained, reaching up to 1.03 % K−1 and 1.07 % K−1 using the FIR strategy, and up to 0.146 % K−1 and 0.47 % K−1 with the FL strategy for Ho3+/Er3+/Yb3+ and Nd3+/Er3+/Yb3+ tri-doped Ba2GdV3O11 phosphors, respectively. Furthermore, the studied phosphors exhibit remarkable precision in detecting minute temperature changes (0.3 K), positioning them as promising candidates for precise temperature sensing. This study pioneers innovative methodologies to advance optical thermometry techniques, offering promising prospects for scientific and industrial applications reliant on precise optical temperature sensing.