激光冲击对氧化石墨烯薄膜的结构及力电性能影响

采用激光烧蚀氧化石墨烯薄膜，可实现其微尺度图案化加工，以应用于微纳米电子器件。但激光冲击下氧化石墨烯薄膜的结构及力、电性能变化直接影响了器件稳定性和可靠性。为研究超高应变率加载对氧化石墨烯薄膜的结构及性能的影响，采用不同功率激光冲击氧化石墨烯薄膜，通过对其表面形貌、化学成分表征揭示薄膜结构的改变机理，通过对薄膜冲击前后的硬度、弹性模量、导电率测试探索合理的激光加工参数。结果表明：在1.14 W功率的二氧化碳激光冲击下，可实现加工区氧化石墨烯薄膜的还原且不造成薄膜烧蚀断裂，其电导率可达到1.727×10³ S/m，弹性模量为49.97 GPa，硬度为5.71 GPa。

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.