Fluorescence spectra and crystal field analysis of BaMoO4: Eu3+ phosphors for white light-emitting diodes

• We demonstrate the red phosphors BaMoO4:Eu3+ excited by the blue light (464 nm).
• These phosphors present the strong emission spectra around 613 nm.
• Their color coordinate values are close to the NTSC standard values.
• The mechanisms for Eu3+ at the Ba2+ site of BaMoO4 were studied by CMD method.
• The fitting values of CMD method are close to the experiment results.

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 Eu3+-doped barium molybdate phosphors effectively excited by the blue light (464 nm). These phosphors present the strong emission spectra around 613 nm 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 Eu3+ ions at the tetragonal (S4) Ba2+ site of BaMoO4 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.

A type of as-grown red Eu3+-doped barium molybdate phosphors shows the strong emission spectra around 613 nm. By constructing a complete 3003 × 3003 energy matrix, for the first time, the spectra positions for Eu3+ ions at the tetragonal (S4) Ba2+ site of BaMoO4 crystal were accurately identified from a complete diagonalization (of energy matrix) method. 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.Figure optionsDownload as PowerPoint slide