Graphene is influenced by its surrounding environment, such as adsorbates, charged impurities, and interface traps, owing to its large surface area and ultra-thin thickness. Herein, the effect of substrate conditions on the doping and degradation of graphene is investigated. The hydroxyl (-OH) groups on the silicon dioxide (SiO₂) substrate formed by oxygen plasma treatment altered the characteristics of the overlying graphene. On exposure to ultraviolet (UV) light, the p-doping level of graphene on oxygen-plasma-treated SiO₂ (P-SiO₂) increased and degradation occurred, while graphene on bare SiO₂ showed no change. The graphene on P-SiO₂ had higher reactivity due to doping induced by –OH groups on the SiO₂ surface. The graphene field-effect transistors (G-FETs) on the P-SiO₂ also showed the reduced carrier mobility and larger shift of charge neutral point. However, during UV exposure, the device showed sever degradation in electrical conductivity and failure after 60 min. Meanwhile, the device on the bare SiO₂ showed negligible changes even after UV exposure. Our results unveil the origin of degradation in the graphene and show a way to prevent the unwanted changes or degradation of graphene, which is highly important for the practical application of graphene.

石墨烯由于其表面积大和厚度超薄而受到周围环境的影响，如吸附物、带电杂质和界面陷阱。在此，研究了衬底条件对石墨烯掺杂和降解的影响。通过氧等离子体处理形成的二氧化硅 (SiO ₂ ) 衬底上的羟基 (-OH) 基团改变了上覆石墨烯的特性。在暴露于紫外线 (UV) 光下时，经过氧等离子体处理的 SiO ₂ (P-SiO ₂ )上石墨烯的 p 掺杂水平增加并发生降解，而裸露 SiO ₂上的石墨烯没有变化。由于 SiO 上的 –OH 基团引起​​掺杂，P-SiO ₂上的石墨烯具有更高的反应性₂表面。P-SiO ₂上的石墨烯场效应晶体管（G-FET）也显示出载流子迁移率降低和电荷中性点偏移较大。然而，在紫外线照射期间，该器件在 60 分钟后显示出电导率严重下降和故障。同时，即使在紫外线照射后，裸露 SiO ₂上的器件也显示出可忽略不计的变化。我们的结果揭示了石墨烯降解的起源，并展示了一种防止石墨烯发生不需要的变化或降解的方法，这对于石墨烯的实际应用非常重要。