Crystal structure and photoluminescence of Tb3+-activated Ba3InB3O9

Subsolidus phase equilibrium of BaO–In2O3–B2O3 system has been investigated mainly by solid-state reaction technique and powder X-ray diffraction method. There are 15 definite three-phase regions under present experimental conditions. Two ternary compounds, Ba3InB9O18 and Ba3InB3O9 were found and confirmed in this system. Crystal structure of Ba3InB3O9 was determined from X-ray powder diffraction data using Rietveld method. It crystallizes in space group image with six formula units of a cell with a = 12.7713(4) Å, c = 9.3950(2) Å and V = 1327.09(8) Å3. Coordination surrounding of B–O in this structure, [BO3]3− group, was confirmed by infrared absorption spectrum of Ba3InB3O9. Ba3In1−xTbxB3O9 (x = 0.1–0.5) phosphors exhibited green emission at about 543 nm with 370 nm light excited. There is neither emission from 5D3 level nor concentration quenching observed in the case of Ba3InB3O9:Tb3+, which can be explained from the crystal structural features of the matrix Ba3InB3O9. Chemical stabilization, simple preparation, and luminescence characteristics make phosphors Ba3InB3O9:Tb3+ have potential applications in white light-emitting diodes.