Reversible Ionizing Radiation Sensors Based on Carbon Nanotubes

Vertically Aligned Carbon Nanotubes (VA-CNTs) were grown by Chemical Vapor Deposition (CVD) on a silicon substrate with alternating layers of TiN and SiO₂. VA-CNTs were exposed to X-ray radiation to study the change in resistivity later. Preliminary results show an increase in the resistivity of CNTs as a function of radiation exposure time, which means that the structure responds successfully to radiation exposure. The variation of resistivity has been associated with the presence of organic compounds that, during exposure to radiation, can generate species capable of interacting with the material by modifying its conductive properties. The first evidence indicates that the changes observed are reversible under heat treatment, which also supports the fact that it is the adsorbed organic species that, in the presence of radiation, modify the resistivity of the material and possibly allowing the material to be recyclable.