Effect of FA: X+3 (X = B, Al, and Ga) Color Centers on the Electronic and Optical Properties of LiF (001) Surface

Abstract

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