Amorphous Germanium Thin Films on Kapton Tape Fabricated Using Electron Beam Evaporation as Flexible γ‐Ray Radiation Monitoring Materials

In this study, amorphous germanium (a‐Ge) thin films on a Kapton tape are fabricated and utilized in monitoring gamma (γ)‐ray irradiation. The flexible Ge thin films are formed using electron beam evaporation without heating of the chamber with a rate of 0.01 Å s −1 . Ultraviolet‐visible‐near‐infrared (UV–vis–NIR) absorption and Raman spectroscopy studies confirm the absorption from the UV to NIR regions and amorphous nature of the thin films, respectively. The X‐ray diffraction and the extended X‐ray absorption fine structure studies demonstrate the atomic structure of a‐Ge thin films, which suggests the possible presence of the macrobending created due of the flexible Kapton tape. The samples are exposed to the γ‐rays with a relatively higher dose up to 5 kGy compared to previous typical values exposed to test Ge‐based thin films. The samples are exposed to the γ‐rays with a dose of 1, 3, 4, and 5 kGy. The structural and optical changes upon the exposure of the γ‐rays demonstrate that flexible Ge thin film can be used in the radiation monitoring up to a dose level of 12 kGy.