A series of phosphors Ca12(0.97-x)Al14O32F2: 0.03Ce(3+), xTb(3+) have been prepared by a hightemperature solid-state reaction using boric acid as flux. These oxyfluorides crystallize in cubic structure, I (4) over tilde 3d space group. Under the near ultraviolet excitation within wavelength range 310-390 nm, Ca12(0.97-x)Al14O32F2: 0.03Ce(3+), xTb(3+) phosphors exhibit an intense emission covering a broad band of 370-500 nm derived from the 5d -> 4f transitions of Ce3+ and a characteristic emission at 544 nm of Tb3+. The emission can be tuned from blue to green by altering the relative ratio of Ce3+ to Tb3+ in the composition. The energy-transfer mechanism from Ce3+ to Tb3+ is investigated based on the site occupancy of the luminescence center in the crystal structure of the Ca12Al14O32F2 host. More importantly, when a certain amount of boric acid is added as flux in the synthesis, the fluorescence intensity of the phosphors increases about 65%. Because of its broad excitation and efficiently tunable blue to green luminescence, the Ca12(0.97-x)Al14O32F2: 0.03Ce(3+), xTb(3+) phosphors may find promising application as a near UV-convertible phosphor for white-light-emitting diodes.