29/05/2024
Metal halide perovskites (MHP) have revolutionised the world of solar energy conversion, thanks to the development of high-efficiency and low-cost photovoltaic cells. But their potential goes far beyond that.
The outstanding electric and optoelectronic properties of MHPs allowed indeed for the development of ultra-sensitive, portable and low-power X-ray detectors, based on both thin films and bulk crystals, for applications in the field of medical diagnostics, homeland security, or aerospace. The main limitation to overcome for the commercialization of perovskite-based X-ray detectors is long-term operational stability, which has so far proven insufficient, and often accompanied by a drastic performance deterioration after only a few hours of irradiation.
In a recent study, carried out in the framework of “PARIDE” (Perovskite Advanced Radiotherapy & Imaging Detectors) project, the team of the Diathema Lab of the Institute of structure of matter (Cnr-Ism), in collaboration with the CHOSE of the University of Rome Tor Vergata and the Niccolò Cusano University, demonstrated that X-ray detectors based on thin films (255 nm) of a specific type of MHP (FAPbBr3), deposited on mesoporous titanium dioxide (TiO2) have exceptional operational stability, and are able to work continuously for 26 days without signal loss. No structural damage occurred after irradiation at a total dose of approximately 200 Gy, demonstrating excellent radiation hardness despite the thin film structure. A bulk sensitivity of 7.28 C Gy−1 cm−3 at 0 V, record in the field of photoconductors and photodiodes for X-rays of energy above 2 keV, was achieved thanks to the presence of a high current gain.
The rationale behind the project idea was to adapt a reliable technology in the field of solar cells (based on extremely stable FAPbBr3/TiO2 structures) to X-ray detection, fabricating devices that can be used indifferently as photovoltaic panels or dosimeters for radiotherapy in the treatment of tumours or for interventional radiology.
For this purpose, the first prototypes were successfully tested at the linear accelerator of the Oncology Radiotherapy department of San Giovanni Hospital in Rome, showing excellent results.
Following the importance of the results obtained, and their significant interdisciplinarity (spanning from energy to life science), the work was recently published in a high impact journal (IF = 26.6) such as Nano-Micro Letters.
Per informazioni:
Marco Girolami
Cnr-Ism
DiaTHEMA Lab
Strada Provinciale 35d, 9 - 00010 Montelibretti (RM)
marco.girolami@ism.cnr.it
Ufficio Comunicazione, Cnr-Ism, comunicazione@ism.cnr.it
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