X-ray qualification of hydrogenated amorphous silicon sensors on flexible substrate

A Hydrogenated amorphous silicon detector for Space Weather Applications

“…Typical deposition temperature should range between 100 • C (to reduce the number of defects in the material) and 350 • C (to avoid desorption of H), and normally occurs around 200 • C Matsuda (2017). This interval of processing temperature allows for the deposition of layers or devices on a variety of substrates, among which thin layers of plastic materials like polymmide Söderström et al (2008), Menichelli et al (2023). The capability of depositing small area devices over a flexible and thin substrate opens the possibility to several applications in different fields among which: instrumented flange at the vacuum/air separation of charged particle accelerators and transmission detectors for dosimetry of real dose delivered to patients by clinical beams in radiotherapy, by considering curved or bent small thickness devices of almost any geometrical shape suitable also for space applications.…”

“…Several devices, both p-i-n diode and CSC have been characterized for noise, leakage current and with ionizing radiation beams at several facilities: X-ray photons (tube voltage up to 50 kV), 6 MV clinical photon beams, 6 MeV electron beams and 3 MeV proton beams Menichelli et al (2022bMenichelli et al ( , 2021. 3 The procedure for measuring the current signals from a device under test is: (i) start the data acquisition with no 3 Facilities used for beam tests: for photons below 50 keV see Menichelli et al (2023).…”

“…8, reaching also 5% for more recent batch of diodes deposited on kapton. The variance for the entire bias range is smaller than 20%, ensuring that the same readout chain would work for all devices after inter-calibration Menichelli et al (2023), Large et al (2023).…”

“…A device capable of photon detection at 4 σ for energies above 5 keV could be built given the available deposition techniques of a-Si:H on kapton substrate Menichelli et al (2023) by considering also a deposition of a metal layer of hundreds of nm on top the sensors for visible light shielding.…”