Chiral inorganic nanostructured BiOBr phosphors co-doped with Er3+ and Yb3+ ions exhibit highly sensitive temperature sensing properties

A series of chiral nanostructured bismuth bromide doped with Er 3+ , Yb 3+ (D-BYE) phosphors were synthesized using a solvothermal method followed by an air annealing strategy. The upconversion luminescence (UCL) spectra were also recorded under 980 nm laser excitation in the temperature range from 295 to 565 K. The UCL intensity of D-BYE is about 34 times higher compared to the achiral nanostructured bismuth bromide doped with Er 3+ , Yb 3+ (A-BYE) phosphor. Optical temperature sensing of phosphors was achieved by evaluating the temperature sensing behavior using thermally coupled (TCLs) or non-thermally coupled (NTCLs) levels of Er 3+ . Impressively, the maximum relative sensitivity (S R ) value of the D-BYE phosphor was 1.32% K -1 using the NTCLs method, which is about 1.6 times higher than the sensitivity of the TCLs-based method (0.86% K -1 ). The results of this work demonstrate the great potential of D-BYE phosphors for optical temperature sensing.