The Quantitative Analysis Of Phosphor Component Based On Terahertz Time Domain Spectroscopy

Technology of the terahertz(THz) wave has been an emerging research area in recent years. THz wave involves abundant physical and chemical information of the substance, so the qualitative and quantitative investigation on the material can be carried out by analyzing the information contained in the terahertz spectrum. In this paper, the Terahertz Absorption Spectra of three kinds of inorganic phosphors have been studied by the THz Time Domain spectroscopy(THz-TDS). Based on three kinds of regression methods, the contents of rare earth elements contained in three kinds of inorganic phosphors have been analyzed. Meanwhile, the physical mechanism of partial absorption peaks in the terahertz spectrum of the phosphor powder has been investigated. The main work of this paper is as follows:1、By terahertz time-domain spectroscopy(Spectra TPS 3000), THz spectra of three kinds of mixtures of inorganic phosphor powder and polyethylene with different mass fraction have been obtained. The absorption coefficients of the mixtures have been get from the optical parameters of the spectra. The content of rare earth elements in three kinds of phosphors have been obtained by the wavelength dispersive X- ray fluorescence spectrometer(Axios Max Petro).2、Three regression methods, including linear regression, partial least squares regression PLS and support vector machine regression(SVR), have been used to analyze the content of rare earth elements of three kinds of typical inorganic phosphor. It is has been proved that these regression methods are suitable to analyze the content of rare earth elements in inorganic phosphor powder, and the suppo rt vector machine regression analysis is the best method.3、Based on the quantum chemistry calculation software, we have researched the mechanism of the partial absorption of terahertz spectrum of the phosphor powder. The comparison of experimental results and theoretical calculation results shows that the absorption peak of the THz spectrum of the phosphors powder is attributed to the vibration of the inner part of the molecular structure.