Electrolytic coloration and spectral properties of hydroxyl-doped potassium chloride single crystals

► Expanded the traditional electrolysis method. ► Hydroxyl-doped potassium chloride crystals were colored electrolytically for the first time. ► Useful V, F and F-aggregate color centers were produced in colored crystals. ► V color centers were produced directly and F and F-aggregate color centers indirectly.