Silicon carbide is the material used to armor electronics. It withstands heat, impacts, and radiation like the ceramic tiles on a spacecraft's heat shield. But even this armor has a weak spot: ordinary metal contacts quickly degrade under X-rays. In the new work, the contact was replaced with a layer of graphene — a carbon film just one atom thick. Graphene conducts electricity but barely interacts with radiation, so the detector stays intact.
After irradiation, the device was tested with fast electrons from radioactive strontium-90. Leakage current rose to 0.22 nanoamperes — a thousand times less than in silicon detectors. Time resolution was 58 picoseconds before irradiation and 64 picoseconds after. One picosecond is one trillionth of a second. In that time, light travels just a third of a millimeter. The detector with the graphene electrode turned out to be 40% more precise than an identical one with a conventional contact.
Such a device fears neither cosmic rays nor radiation at a nuclear plant. It can be installed in particle accelerators, satellites, and reactor monitoring systems. The graphene film works like an invisible shield: it lets the signal through but doesn't break down itself. This is a step toward electronics that lasts for decades where ordinary chips die within hours.
Graphene is the thinnest material in the world: a sheet the size of a football field would weigh less than one gram.