Luminescence properties of Eu²⁺/Mn²⁺ codoped borophosphate glasses

On the basis of the glass network structure and spectroscopy information, the full-color-emitting borophosphate glasses doped/codoped with Eu²⁺ and Mn²⁺ ions were synthesized, and their photoluminescence (PL) properties were evaluated. The interaction of Mn²⁺-Mn²⁺ pairs shifts its emission to longer wavelength without a notable negative effect on the intensity in Mn²⁺-doped glasses. Depending on the small amount of B₂O₃ added, the Mn²⁺ ions suffer different surrounding environments giving three emission bands at 526, 597, and 638 nm, respectively. In codoped samples, the weak red emission resulting from the forbidden transition of Mn²⁺ could be enhanced by the energy transfer from Eu²⁺ because of the spectral overlap between the PL excitation spectrum of Mn²⁺ and the PL spectrum of Eu²⁺. The energy transfer process was confirmed by the luminescence spectra, transmittance spectra, and the calculation of energy transfer efficiency of the glasses. Meanwhile, the potential mechanism of energy transfer is evident to be dipole-dipole interaction. Finally, the Eu²⁺-Mn²⁺-codoped borophosphate glasses showed an adjustable full-color emission that could be regarded as a good candidate for ultraviolet light-emitting diode (LED) chip-based white LEDs.