Transition metal impurities such as nickel, copper, and iron, in solid-state materials like silicon have a significant impact on the electrical performance of integrated circuits and solar cells. To study the impact of copper impurities inside bulk silicon on the electrical properties of the material, one needs to understand the configurational space of copper atoms incorporated inside the silicon lattice. In this work, we performed ReaxFF reactive force field based molecular dynamics simulations, studying different configurations of individual and crystalline copper atoms inside bulk silicon by looking at the diffusional behavior of copper in silicon. The ReaxFF Cu/Si parameter set was developed by training against DFT data, including the energy barrier for an individual Cu-atom inside a silicon lattice. We found that the diffusion of copper atoms has a direct relationship with the temperature. Moreover, it is also shown that individual copper atoms start to clusterize inside bulk silicon at elevated temperatures. Our simulation results provide a comprehensive picture of the effects of temperature and copper concentration on the crystallization of individual copper inside silicon lattice. Finally, the stress-strain relationship of Cu/Si compounds under uniaxial tensile loading have been obtained. Our results indicate a decrease in the elastic modulus with increasing level of Cu-impurity concentration. We observe spontaneous microcracking of the Si during the stress-strain tests as a consequence of the formation of a small Cu clusters adjacent to the Si surface.
A ReaxFF-based thermomechanical analysis of N-carbophenes: phase-change, thermal expansion, and high temperature synthesis pathway
University of Hawai‘i at Mānoa（夏威夷大学马诺阿分校）；Phil and Penny Knight Campus for Accelerating Scientific Impact（菲尔和佩妮·奈特加速科学影响校园）；Dotquant LLC（Dotquant有限责任公司）；Department of Biochemistry, University of Washington（华盛顿大学生物化学系）；University of Hawai‘i Maui College（夏威夷大学茂宜学院）；New Mexico State University（新墨西哥州立大学）；Universidade Estadual Paulista, UNESP（圣保罗州立大学）；Pennsylvania（宾夕法尼亚）
ORION: Unifying Top-Down and Bottom-Up Chemical Space Sampling for a Universal Organic Force Field
Future Technology School, Shenzhen Technology University（深圳技术大学未来技术学院）；College of Applied Sciences, Shenzhen University（深圳大学应用科学学院）；Heilongjiang Provincial Key Laboratory of Oil & Gas Chemical Technology, Northeast Petroleum University（东北石油大学油气化学技术黑龙江省重点实验室）；Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University（清华大学化学工程系绿色化学反应工程与技术北京市重点实验室）；School of Science, Harbin Institute of Technology, Shenzhen（哈尔滨工业大学（深圳）理学院）；School of Energy and Power Engineering, Dalian University of Technology（大连理工大学能源与动力工程学院）；Department of Chemical and Materials Engineering, University of Alberta（阿尔伯塔大学化学与材料工程系）
