The nanofriction properties of hexagonal boron nitride (h-BN) are vital for its application as a substrate for graphene devices and solid lubricants in micro- and nano-electromechanical devices. In this work, the nanofriction characteristics of h-BN on Si/SiO₂ substrates with a bias voltage are explored using a conductive atomic force microscopy (AFM) tip sliding on the h-BN surface under different substrate bias voltages. The results show that the nanofriction on h-BN increases with an increase in the applied bias difference (V_t−s) between the conductive tip and the substrate. The nanofriction under negative V_t−s is larger than that under positive V_t−s. The variation in nanofriction is relevant to the electrostatic interaction caused by the charging effect. The electrostatic force between opposite charges localized on the conductive tip and at the SiO₂/Si interface increases with an increase in V_t−s. Owing to the characteristics of p-type silicon, a positive V_t−s will first cause depletion of majority carriers, which results in a difference of nanofriction under positive and negative V_t−s. Our findings provide an approach for manipulating the nanofriction of 2D insulating material surfaces through an applied electric field, and are helpful for designing a substrate for graphene devices.

六方氮化硼（h-BN）的纳米摩擦特性对于将其用作石墨烯设备的基材以及微机电和纳米机电设备中的固体润滑剂至关重要。在这项工作中，使用在不同衬底偏压下在h-BN表面上滑动的导电原子力显微镜（AFM）尖端探索了具有偏压的Si / SiO ₂衬底上h-BN的纳米摩擦特性。结果表明，在h-BN上的纳米摩擦随着导电尖端和基板之间施加的偏压差（V _t-s）的增加而增加。负V _t-s下的纳米摩擦大于正V _t-s下的纳米摩擦。纳米摩擦的变化与由充电效应引起的静电相互作用有关。随着V _t-s的增加，位于导电尖端和SiO ₂ / Si界面的相反电荷之间的静电力增大。由于p型硅的特性，正V _t-s首先会导致多数载流子耗尽，这将导致正负V _t-s下纳米摩擦的差异。我们的发现提供了一种通过施加电场来控制2D绝缘材料表面的纳米摩擦的方法，并有助于设计用于石墨烯器件的基板。