Superconductivity, quantum capacitance, and electronic structure investigation of transition metals (X = Y, Zr, Nb, Mo) encapsulated silicon nanoclusters (Si59X): Intuition from quantum and molecular mechanics

Abstract

Silicon nanoclusters (SiNCs) have unique structural and electronic properties that make them promising candidates for energy storage devices such as batteries, supercapacitors, and solar cells. This study theoretically investigated the superconducting and capacitance properties of transition metal (TM) doped silicon nanoclusters using density functional theory (DFT) calculations. The electronic and ionic conductivity, as well as the non-linear optic property, of TM-doped silicon nanoclusters herein, were analyzed to determine their potential as capacitor electrodes. The effects of temperature on electronic and ionic conductivity were also studied. The results suggest that TM doping enhances the superconducting and capacitance properties of silicon nanoclusters. The electronic conductivity was found to increase with increasing temperature, while the ionic conductivity showed a nonlinear relationship with temperature. Furthermore, it was observed that the doping of studied certain TM elements, such as Nb and Mo, leads to the formation of metallic states within the HOMO-LUMO energy range, indicating their potential for superconducting behaviour. The HOMO-LUMO analysis also reveals the electronic band structure and the bandgap of TM-doped silicon nanoclusters, showing that the dopants can tune the bandgap, resulting in improved superconductivity capacitance. The NBO analysis reveals the nature of bonding between the dopant atoms and the silicon atoms, indicating that charge transfer between the dopants and the silicon atoms plays a crucial role in enhancing the electronic properties Additionally, the stability of TM-doped silicon nanoclusters was analyzed, and it's found that the doping with TM elements resulted in stable structures. The result strongly suggested that doping with Y, Zr, Nb, and Mo enhances the capacitance at different voltages and conductivity at elevated temperatures especially as the electronic configuration of the d-orbital of the dopant evolves. Overall, this study provides valuable insights into the potential of TM-doped silicon nanoclusters as efficient materials for superconducting and capacitive applications.