Energy Transfer from Pr(3+) to Gd(3+) and Upconversion Photoluminescence Properties of Y(7)O(6)F(9):Pr(3+), Gd(3+)

Upconversion materials have numerous potential applications in light energy utilization due to their unique optical properties. The use of visible light excitation to obtain ultraviolet emission is a promising technology with broad application prospects, while relevant research is absent. A series of Pr(3+), Gd(3+) doped Y(7)O(6)F(9) phosphors were synthesized by traditional solid–state reaction. X-ray diffraction, scanning electronic microscopy, steady-state photoluminescence spectra, a decay dynamic, and upconversion emission spectra of the samples were studied. Under the excitation of 238 nm, the energy transfer from Pr(3+) to Gd(3+) was realized and a strong ultraviolet B emission due to the (6)P(7/2)→(8)S(7/2) transition of the Gd(3+) ions was achieved. Under the excitation of a 450 nm blue laser, Pr(3+) absorbed two blue photons to realize the upconversion process and then transferred the energy to Gd(3+) to obtain the ultraviolet B emission.