Impact of Transition Metals—Cr, Mn, and Fe Dopants on Graphene‐Like Group‐IV Nanosheets: A DFT Study
Noor Ahammad, Aoly Ur Rahman, Md. Alamgir Kabir, Md. Kabir Uddin Sikder
Abstract
Nanotechnology has undergone a revolutionary transformation since the discovery and synthesis of two‐dimensional (2D) graphene nanosheets, inspiring researchers to explore the properties of other 2D nanosheets. In this work, using density functional theory (DFT) calculations, we have explored the structural, thermodynamic, and electronic properties of graphene‐like 2D nanosheets: silicene (Si), germanene (Ge), and stanene (Sn), and the impact of transition metals (TMs)—Cr, Mn, and Fe on these structures. All the pristine and TM‐doped Si, Ge, and Sn nanosheets are likely to be formed naturally to their true energy minima, as none exhibit any molecular vibration in the imaginary frequency range, as confirmed by the infrared (IR) spectroscopy study. Moreover, compared to the pristine nanosheets, TM‐doped structures have significantly higher molecular stability since the average binding energy (ABE) negatively increases almost three times after being doped with these studied TMs. Additionally, the thermodynamic properties analyses have shown that doping Si, Ge, and Sn nanosheets with Mn or Fe increases the thermodynamic stability of the structures, whereas doping with Cr shows the opposite behavior, which confirms the former results. The favorable electric energy, including the reduction in the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap (0.89–1.33 eV) due to doping with TMs, signifies their credibility to be used as an alternative to typical semiconductors in various devices. Taking these together, the Mn dopant significantly improves the structural, electric, thermodynamic, and magnetic properties of pristine Si, Ge, and Sn nanosheets, making them promising technologies, such as supercapacitors, nanosensors, spintronics, and energy storage devices.