Space irradiation-induced damage to graphene films.

Graphene with impressive electrical, optical, chemical and mechanical properties has promising potential applications for photoelectric devices and mechanical components installed on the space facilities, which will probably face hostile environments including high-energy particulate irradiation. Here we explored the effect of simulated space irradiation on the structure and properties of large-area single-layer and multi-layer graphene films (about four layers) including atomic oxygen (AO), electron (EL) and proton (PR). AO with strong oxidizing capacity reacts with carbon atoms of graphene films and generates carbon dioxide, high-energy PR leads to polymorphic atomic defects in graphene through collision and excitation effects. Miraculously, EL irradiation causes little damage to the graphene films because of the excellent conductivity. Graphene ripples are broken by irradiation and adapt their shape or structure with respect to the substrate via thermodynamic stability, which causes the change of the physical and mechanical properties of graphene.