Abstract
The density functional theory and configuration interaction single excitations methods were used to study the effect of F-A color centers on the electronic and optical properties of the LiF (001) surface. Three types of F-A color centers were used, F-A: B+3, F-A: Al+3, and F-A: Ga+3. The evaluated values of the ionization potential, chemical hardness, and softness indicate the stability of the investigated color centers. F-A: B+3 is the most stable one. While the electron affinity values reveal that the F-A: Al+3 center is the highest reactive one. The Ultraviolet-Visible spectra for F-A: B+3, F-A: Al+3, and F-A: Ga+3 centers showed that the scrutinized centers have two absorption peaks. The highest absorption peak recorded for FA: B+3 center is located at 285 nm, while the highest absorption peaks recorded for F-A: Al+3, and F-A: Ga+3 centers are located at 173 and 165 nm, respectively. According to the light- harvesting efficiency values, F-A: Al+3, and F-A: Ga+3 centers have the highest efficiency to gather the energy during the pumping process than F-A: B+3 centers. Stokes-shift values for F-A: B+3, F-A: Al+3, and F-A: Ga+3 centers were 0.16, 0.37, and 0.33 eV, respectively, consequently, F-A: Al+3 and F-A: Ga+3 centers, are more suitable for laser production than F-A: B+3 center.