Fabrication of Nanoscale Cesium Iodide (CsI) Scintillators for High-Energy Radiation Detection

Abstract

The CsI-based scintillators have been widely used for X-or gamma-ray detections. It has been known that columnar scintillators favor the detections with higher efficiency and spatial resolution. In this paper, we report a facile and low-cost method to fabricate submicron nanoscale CsI columns. We integrated the thermodynamic calculations, positive chamber design, mold design, electrochemical bath design, anodization process, and solidification techniques to fabricate such submicron CsI columns. When the CsI melt is confined to AAO channels with a high aspect ratio, stable CsI columns solidified with smooth surfaces, and free of dendrites or grain boundaries. Different solidification approaches have been attempted, including mechanical injection in vacuum under a negative pressure, injection at 1 atm, 3 atm and 25 atm using Ar gas only, and mechanical injection with 1.6 atm Ar pressure. The mechanical injection or high-pressure Ar injection at 25 atm produced good filling of CsI melt into AAO channels. Such CsI columns inside the smooth AAO walls enable the highenergy radiation detection with high light emission for pixelated scintillator applications.

Amorphous BaTiO3 Electron Transport Layer for Thermal Equilibrium‐Governed γ‐CsPbI3 Perovskite Solar Cell with High Power Conversion Efficiency of 19.96%

“…[ 34 ] The absence of burning and charging effects on the samples led us to believe that the residues were inorganic rather than organic, such as remaining DMAI. [ 34,35 ] Additionally, the morphology of the DMAI residues was not observed in the samples. At 10% and 20% RH, comparable dense thin films with large grain size (~400–900 nm) were observed (Figure 1f,g).…”

“…On the basis of our observations and results, we propose that changes in the optical bandgap of γ‐CsPbI 3 are more likely to be caused by the insertion of the Cs ion into the 3D framework than by DMAI species remaining in the perovskite film after annealing. Owing to their hygroscopicity, [ 35 ] Cs ions can readily intercalate into the perovskite structure in the presence of moisture, enabling the formation of a distortion‐relieved structure with a relatively narrower bandgap. We acknowledge that the calculation of band dispersion is valid, but the calculated bandgap is quantitatively underestimated because of the well‐known PBE functional limitation.…”

Development of an Energy-Sensitive Detector for the Atom Probe Tomography

“…Indeed in 1955, Murdock et al reported that CFs have one of the highest SEY compared with most other materials (Murdock & Miller, 1995). Although there are exceptions such as cesium iodide (CsI) thin foils, which produce much higher SEYs (Chianelli et al, 1988), but there are difficulties to manufacture robust and regular thicknesses of CsI under 100 μm (Weathers & Tsang, 1996;Chen et al, 2015). In fact, Maier-Komor (1993) reported that CFs can be manufactured one order of magnitude thinner than foils made with other elements, with thicknesses below 5 nm.…”

Fabrication of Energy Materials by a Functional Electrochemical Mold

“…In our previous work, we have made small sampled of AAO template and TiO 2 NT for academic research of nano-wires, nano-whisks, nano-spheres, and solar cell [5][6][7][8].…”