I2DM: A Monte Carlo framework for ion irradiation on two-dimensional materials

Recent years have witnessed a surge of research on the structure, property and performance engineering of two-dimensional (2D) materials by ion irradiation. Compared to the 3D counterparts, 2D systems exhibit drastically different and even counter-intuitive irradiation response, and an atomic insight into the ion bombardment and defect formation is essential. In this work, we develop a theoretical framework I2DM for simulating ion irradiation on two-dimensional (2D) materials using Monte Carlo (MC) algorithm. I2DM can generate incident ions with adjustable ion species, incident energy, ion fluence and incident angle. Based on binary collision approximation (BCA), the primary collisions, cascade collisions and defect recombination during irradiation process are explicitly described. As output, details on the defect type/yield and morphology of irradiated material are provided. We have performed systematic simulations on three typical 2D structures, including graphene, h-BN, and MoS_2 under different ion irradiation conditions, and reveal that the obtained results are in excellent agreement with the available experimental measurements and molecular dynamics data. The developed framework is generally applicable and computationally efficient, highly valuable for understanding the fundamental mechanism of ion irradiation on 2D systems and designing/optimizing low-dimensional structures for nanoelectronics, spintronics, optics, energy storage and environmental protection.