High-throughput calculation of interfacial friction of two-dimensional materials

Friction generally happens during relative motion or the tendency of relative motion at the contacting interface, impeding the relative motion and consuming extra energy. Micro-scale friction shows difference to the macro-scale friction due to surface effects and other factors, It is necessary to study the friction behavior at nano-scale. First-principles method is an important way to study and understand friction at nano-scale. Nevertheless, constructing nearly a thousand models and the processing of a large number of data is very time consuming. In this paper, we have established a high-throughput computational program based on the first-principles method to study the interfacial friction of two-dimensional materials. The program realizes modeling, submitting computation tasks, multi-task concurrent calculation, data collection and processing, and image rendering of calculation results. All of these are done in batch automatically, which greatly saves researchers' time. In this paper, this program is used to simulate the normal load by changing the distance between layers and calculate the potential energy surface of BN/BN and graphene/graphene bilayer sliding systems at series interlayer distances, as well as the interlayer friction force and friction coefficient. The study found that with the decrease of the interlayer distance, the averaged friction force at BN/BN interface increases approximately linearly, and the friction coefficient was 0.11 ~ 0.17. The friction force at graphene/graphene interface firstly increases, then decreases, and then increases again. The friction coefficient reaches a minimum value (0.014) under a load of 12 nN, and these results are consistent with the previous results, verifying the reliability of the calculation program. In addition, we investigated the effect of surface hydrogenation and fluorination on the tribological property of the BN bilayer and found that the friction at the fluorinated BN/BN interface is reduced attributed to the smaller charge transfer at interface. Although the high-throughput calculation method realizes the automation and high-throughput calculation of tribological property at solid interface, there are still some limitations. First of all, the effect of interlaminar bending is not considered in the process of interlaminar relative sliding. secondly, the essence of the calculation result is static friction, not dynamic friction. In addition, the method does not consider the influence of temperature.