Study of humidity on the structure and optical properties of cesium iodide thin film

Abstract

Abstract We report the influence of 70% 5% humid exposed air at room temperature on the structure of 500nm thick CsI film. By means of scanning electron microscopy (SEM) and X- ray diffusion (XRD) analysis, the surface morphology and polycrystalline structure were investigated. After 24 hour exposure to humid air, the grain size of CsI film has a drastic change, and so as to the preferential growth orientation. Infrared spectra showed a hydroxyl absorption peak after 3h exposure. And in long term exposure (24h), the absorption peak broadened with the band center shifting toward lower wavenumbers.