The fabrication of sub-micron size cesium iodide x-ray scintillator

Abstract

The cesium iodide (CsI) scintillator can converts incident X-ray into visible light with very high conversion efficiency of optical photons. The incident energy, response time, film thickness, sample size, and spatial resolution require in engineering and medical applications are difference. A smooth and flat surface and single crystal structure of CsI enhance the X-ray to visible light conversion. However, the regular CsI is soft and extremely hygroscopic; it is very difficult to polish to obtain a smooth and optical flat plane. In order to obtain a good quality of CsI scintillator for X-ray application we used an ordering channel as template and formed sub-micron CsI wire in the template. The fabrication process including: (1) Ordering structure of nano or sub-micron channels were made by an anodization method; (2) fill CsI scintillated film on the channel by CsI solution, (3) fill CsI melt into the channel formation single crystal of sub-micron crystalline scintillator after solidification. The non-vacuum processes of anodization and solidication methods were used for the sub-micron CsI scintillator column formation that is cost down the scintillator fabrication. In addition, through the fabrication method, the ordering structure scintillator of scintillator can be made by anodic treatment and die casting technology with low cost and rapid production; moreover, the film oxidized metal tubes of the tubular template can be further manufactured to nano tubes by adjusting electrolyte composition, electrolysis voltage, and processing time of anodic treatment, and the aperture size, the thickness and the vessel density of the nano tube can be controlled and ranged from 10 nm to 500 nm, 0.1 μm to 1000 μm, and hundred million to thousand billion tube/cm 2 , respectively.

Morphologically controlled synthesis of ionic cesium iodide colloidal nanocrystals and electron beam-induced transformations

“… 6–10 The size reduction of CsI from bulk crystals to NCs possibly leads to three-dimensional confinement and more overlap of electron and hole wavefunctions, resulting in optical transitions with higher efficiency and faster rates. 11–13 Therefore, the use of CsI NCs as nanoscitillators is expected to eliminate the issue of slow response of conventional scintillator detectors, and the excellent solubility of CsI colloidal NCs in organic solvents also enables solution-processable devices with low cost. However, the controlled synthesis of high-quality CsI colloidal NCs with tunable morphologies still remains a challenging task, 14 due to its ionic characteristics as mentioned above.…”