Fluorescence spectra and crystal field analysis of BaMoO(4): Eu(3+) phosphors for white light-emitting diodes

The red phosphors play a vital role in controlling luminous efficiency, color rendering index and adjustability in color temperature of white light emitting diodes (w-LEDs). Here, we demonstrate a type of red-emitting phosphors Eu(3+)-doped barium molybdate phosphors effectively excited by the blue light (464nm). These phosphors present the strong emission spectra around 613nm and their color coordinate values are close to the NTSC standard values. More importantly, by constructing a complete 3003×3003 energy matrix by an effective operator Hamiltonian including the free ion and crystal field interactions, for the first time, the fluorescent mechanism for Eu(3+) ions at the tetragonal (S4) Ba(2+) site of BaMoO(4) crystal were investigated by a complete diagonalization (of energy matrix) method (CMD). The fitting values are close to the experimental results, demonstrating the feasibility of using the complete diagonalization method to study the phosphors for w-LEDs.