Morphology, optical and scintillation properties of Eu~(2+)-sensitized CsI(Na) thick film

摘要

Europium and Sodium co-doped CsI and CsI(Na) thick films are deposited by thermal evaporation on the quartz substrate coated with a nano-reflective layer. The morphology and crystal structure of the deposited films, using the SEM images and the X-ray diffraction patterns, exhibited no distinguishable differences. Inductively coupled plasma optical emission spectroscopy ICP (OES) was utilized to measure sodium and europium concentrations in the deposition. Moreover, their optical properties were investigated by UV absorption, excitation, and emission spectroscopy in the wavelength region of 200-800 nm. The results indicated that Eu-sensitizing material enhanced the absorption and photoluminescence intensity of the CsI(Na) columnar-structure film compared to that of conventional CsI(Na) scintillator. This increase was attributed to both the Eu 's high quantum efficiency and the energy transfer between the activator and sensitizer. Ion beam-induced luminescence (IBIL) measurements also confirmed the photoluminescence results. Gamma rays spectroscopy testified to the improvement of CsI(Na, Eu) scintillation efficiency in comparison with the traditional CsI(Na) scintillator.