Preparation, characterization and photoluminescence properties of BaB2O4: Eu3+ red phosphor

A new red emitting BaB2O4: Eu3+ phosphor was synthesized by solid-state reaction method. X-ray powder diffraction (XRD) analysis confirmed the monoclinic formation of BaB2O4. Field-emission scanning electron-microscopy (FE-SEM) observation indicated that the microstructure of the phosphor consisted of irregular grains with heavy agglomerate phenomena. Upon excitation with 394 nm light, the BaB2O4: Eu3+ phosphor shows bright red emissions with the highest photoluminescence (PL) intensity at 611 nm due to 5D0 → 7F2 transitions of Eu3+ ions. The CIE chromaticity coordinates are calculated from the emission spectrum to be x = 0.64, y = 0.35. The effects of the Eu3+ concentration on the PL were investigated. The results showed that the optimum concentration of Eu3+ in BaB2O4 host is 6 mol% and the dipole–dipole interaction plays the major role in the mechanism of concentration quenching of Eu3+ in BaB2O4: Eu3+ phosphor. The effect of charge compensation on the emission intensity was also studied. The charge compensations of Li+, Na+ and K+ anions all increased the luminescent intensity of BaB2O4: Eu3+. K+ anion gave the best improvement to enhance the intensity of the emission, indicating K+ is the optimal charge compensator. All properties show that this phosphor could serve as a potential candidate for application as a red phosphor for NUV chip LED.

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► A new red-emitting phosphor BaB2O4: Eu3+ was prepared at low temperature (800 °C).
► The phosphor BaB2O4: Eu3+ shows bright red emissions excited at 394 nm.
► BaB2O4: Eu3+ exhibits appropriate CIE chromaticity coordinates (x = 0.64, y = 0.35).
► Dipole–dipole interaction is the major mechanism of concentration quenching of Eu3+.
► K+ is the optimal charge compensator for BaB2O4: Eu3+.