The Thermal Stability Prediction Of Graphynes

During the past decades, Integrated circuit technology had been developing rapidly. However, along with the microelectronic devices’ miniaturization in size, some vital physical problems were encountered. In2010, graphyne films were successfully synthesized, showing some semiconductor properties, which is comparable to silicon. After that, graphyne nanotube array and nanowire were also successfully synthesized. Therefore, graphyne is hopefully supposed to replace silicon to be the core material in next generation’s integrated circuit. But so far, there has been no report that single-layer graphyne had ever been successfully synthesized. So the following questions must be addressed:1. How long is the lifetime of the sinlge-layer graphyne at room temperature and above temperature?2. Is the sinlge-layer graphyne able to stably exist like graphene in vacuum?Recently, a statistical model, basded on single-atom, was established to predict the lifetime of nanodevices and surface adatom’s free diffusion rate. In this paper, we will use this model to predict the stability of α-, β-,6612-graphyne and graphdiyne. In order to test the accuracy of our model, we performed a great deal of MD simulations. Results indicate that the time got by the molecular dynamics simulation coincide well with our model prediction. Furthermore, we calculated the potential energy curve along minimum energy path for the defect formation in α-, β-,6612-graphyne and graphdiyne via ab intio, getting that the energy barrier were5.83eV,4.35eV,4.32eV and3.72eV, respectively. Then single-atom statistic model was used to calculate the lifetime of graphynes at different temperature. The results show that the lifetimes for all graphynes are more than1044years room temperature. They are still stable even the temperature rises to1000k. But in2000k, defects are forming rapidly, and graphyne will soon transform into graphene.