X-raying the Universe

X-rays and gamma rays are the signatures of the high-energy Universe. Because they are absorbed by Earth's atmosphere, space telescopes are the only way of detecting them. Currently X-ray and gamma-ray astronomy at ESA are covered by the XMM-Newton and Integral missions. Due to launch in the 2030s, Athena represents the next generation of missions to observe the hot and energetic Universe.

But a big challenge with these missions is image the Universe at these wavelengths with a high enough spatial resolution. To tackle this challenge, ESA Discovery is funding the Italian Institute of Technology (IIT) to explore whether we can make a lightweight, robust and high sensitivity detector for high-energy photons to be deployed in space.

Lorenzo Maserati from IIT explains: "This kind of research has not been attempted before. Our proposal is to use innovative organic-inorganic semiconductors called metal halide perovskites to make compact and lightweight x-ray or gamma-ray detectors that can be put in orbit. Hybrid perovskites are versatile semiconductors equipped with heavy metals that can efficiently stop high-energy rays and extract their photo-generated electrons in a small volume. Our idea is to insert this material into a micro-fabricated 3D metal structure."

"The ESA Discovery funding allows the deployment of this idea into a proof-of-concept device. Our materials research will take a step forward by proving an important space application and it will open new horizons for our group towards the microfabrication of complex perovskite-based devices. The new technology could also be used in terrestrial applications; the healthcare industry, for example, could be interested in having large area thin detectors for medical diagnostics."

ESA engineer Matthew Soman explains: "The detector technology being studied in this activity has the potential to replace the current state of the art in detecting high energy X-ray and gamma ray photons. We're looking forward to seeing how the perovskite-based structures that shall be manufactured and tested compare to the current state of the art and learning more about their suitability for use in future space missions."

This is just one of many activities that ESA Discovery has funded IIT to undertake over the past four years. Lorenzo highlights the impact of this funding: "ESA Discovery has been crucial for the establishment of space activity at IIT. OSIP has been the original method for making IIT colleagues understand that space is something where they can provide a strong contribution. Thanks to OSIP and to some other national actions, in December 2021 IIT established the SPAce CEnter for Innovative & Interdisciplinary Technology (SPACEiit). SPACEiit is also going to enter in the new IIT strategic plan, pushing space activities to achieve a prime role at the institution."