A master’s dissertation in the College of Science has discussed the effect of doping with silicon and germanium on the properties of monolayer carbon nanotubes using the density functional theory by a student Refkah Falah Diab aimed to study the structural and electronic properties of pure monolayer carbon nanotubes and the effect of doping them with silicon Si and germanium atoms on those properties.
The study included the use of density functional theory (DFT) and B3LYP as an exchange-correlation function and a baseline within the Gaussian 09 program, as well as the study of binding energies, formation, cohesion and energy gap.
The study concluded that doping single-layer carbon nanotubes with silicon and germanium led to reducing the energy gap, increasing its effectiveness and electrical conductivity, and possessing electron-donating properties, which enhances the use of silicon-doped carbon nanotubes in lithium batteries. It also improves their electrical conductivity and the use of germanium-doped carbon nanotubes in solar cells. It improves its performance by expanding the light absorption range and enhancing photovoltaic efficiency.
The thesis has recommended applying the study practically by expanding the study of the structural and electronic properties of single-layer carbon nanotubes doped with a greater number of silicon and germanium atoms and studying their optical and spectral properties.