Fluorescence stress sensing with SrSiAlN3:Eu2+ phosphor-silicone composite

Abstract

An experimental piezospectroscopic system was built to study the stress sensing properties of SrSiAlN₃:Eu²⁺ phosphor-silicone composite. A novel technique named barycenter technique was used to analyze the stress-dependent spectra, and accordingly stress sensing functions were obtained. Shape and area of the sample surface on which compressive stress was applied didn’t affect the sensitivity. Stress tests on the experimental setup showed good repeatability for sensing applications. The barycenter technique gave linear stress sensing functions in this research, and finally the determined sensitivity was 0.20 nm/MPa averagely. This sensitivity is one thousand times larger than the piezospectroscopic coefficient of ruby.