Effects of laser irradiation on the structure and mechanical-electrical properties of graphene oxide thin films

Graphene has high specific strength and stiffness, high current-carrier mobility, low resistivity, and even exceptive electromagnetic properties, which is expected as a next-generation micro-nano photoelectric material. However, most research and applications of graphene materials and photoelectric devices are still only in the laboratory stage. On the one hand, limited to current technologies, industrial mass-scale production of high-quality monolayer graphene films is impossible. On the other hand, the micro-scale patterned machining process may bring structural and performance damage to the material, making the stability and reliability of devices difficult to guarantee. In recent years, with the innovation and progress of laser processing technology, the micro-nano-scale patterned processing of graphene oxide (GO) thin films by laser has become a key technology for solving the development of integrated circuits and information communication equipment to precision and miniaturization. The existing achievements mainly focus on the process and method of laser processing graphene materials with different structures, the physical mechanism of interaction between ultrafast laser and monolayer graphene film, etc. The deformation and damage mechanism of graphene films at ultra-high strain rates are still unclear. In particular, the industrial application of micron-scale multilayer reduced graphene oxide (RGO) films has been much widely explored. However, few studies have been conducted on their mechano-thermal and complex physical processes associated with laser shock and the resulting interlayer damage due to the weak interlayer bonding force. To study the effect of ultrahigh strain rate load on the structure and properties of GO films, GO films were prepared by pumping a certain concentration of GO solution onto the membrane. The reduced GO films were obtained by laser ablation with different laser powers. The mechanism of the film’s structural change was revealed by the characterization of its surface morphology and chemical composition. Reasonable laser machining parameters were explored by measuring the hardness, elastic modulus, and conductivity of film before and after impact. The results show that the film can be reduced without ablative fracture under CO2 laser shock at 1.14 W power. Its electrical conductivity can reach 1.727×103 S/m, the elastic modulus is 49.97 GPa, and hardness is 5.71 GPa. © 2022 Explosion and Shock Waves. All rights reserved.