Abstract: A process for the dry synthesis of a luminophore of formula Ax[BFy]:C includes a stage of providing an initial composition comprising at least two synthetic precursors and at least one chemical doping source, a stage of heating the initial composition up to a fluorination temperature under an inert atmosphere or under vacuum, a stage of treatment under a fluorine atmosphere of the composition obtained on conclusion of the heating stage and a stage of returning to ambient temperature under an inert atmosphere. A composition comprising a luminophore of formula Ax[BFy]:C and obtained according to the synthetic process described above, the composition being devoid of hydrogen fluoride.