This study reports the influence of the boron alloying on the structural and optical properties of GaAs compound for the first time. UV-Vis-NIR spectrophotometer, interferometer, photoluminescence spectrophotometer, X-ray diffraction, field emission scanning electron microscopy, and atomic force microscopy tools were used for the determination of the structural and optical properties. As results, boron atoms affect the bang gap to upper energy level with very small variations. But, structural properties and grain dimensions of GaAs have improved by adding boron atoms. The results show that used method, thermionic vacuum arc, is the fast, direct, environmental and very easy-doped BGaAs ternary compounds deposition method according to other methods. Finally, this method is a promising method for GaAs technology.