Magnetron Sputtered CsPbCl3 Perovskite Detectors as Real-Time Dosimeters for Clinical Radiotherapy

The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radio-therapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications.Thin (≈1 micron) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl3, have been grownfor the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have beentested in real-time configuration to evaluate the dose delivered by a 6MV photon beam from a linear accelerator. Linearityof the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose ratehas been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and widebandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configurationallows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the activevolume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatialresolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generationof flexible, transmission, real time dosimeters for clinical radiotherapy.