Investigation of red-emitting Bi4Si3O12:Eu3+ phosphor under the deep UV irradiation as a novel material for white light and color tunable emission

Bi4Si3O12:Eu3+ phosphors are synthesized by a solvothermal reaction method. The structural properties are investigated using the X-ray diffraction patterns, which confirmed the cubic phase with a space group I-43d. The optical properties are studied by the measurement of diffused reflectance, excitation and emission spectra. The photoluminescence (PL) excitation spectra of Bi4Si3O12:Eu3+ phosphor exhibits a broad band between 220 and 350 nm with two peaks occurring around 271 and 297 nm corresponding to the host absorption and charge transfer bands, respectively, and several sharp peaks due to the f-f transitions of Eu3+ ions in the wavelength over 350 nm. The PL spectra exhibit blue emission due to the 1S0 → 3P1 transition of Bi3+ and red emission due to the 5D0 → 7F2 transition of Eu3+. With increase of Eu3+ concentration, blue emission decreased and red emission increased. At the concentration of 3 mol% Eu3+, Bi4Si3O12:Eu3+ phosphors show white emission with the CIE chromaticity coordinates (x = 0.345, y = 0.327). These results suggest that the Bi4Si3O12:Eu3+ phosphors are promising luminescence materials for UV based white light emitting diodes.