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A series of tunable blue-green emitting phosphors Al 5 O 6 N: Eu2+, Tb3+ were prepared via gas-pressure sintering reaction process. The morphology, UV–Vis reflectance spectra, photoluminescence properties, decay behavior, Eu2+ occupy site, energy transfer mechanism and thermal stability were investigated systematically. The Al 5 O 6 N: 0.003Eu2+, 0.01Tb3+ phosphor exhibits strong green emission under near-UV excitation due to briskly efficient energy transfer from Eu2+ to Tb3+. The maximum energy transfer efficiency calculated by decay lifetime can reach 80%. The mechanism of energy transfer from the Eu2+ to Tb3+ is considered to be a dipole−dipole type. The critical distance of the energy transfer is calculated via the concentration quenching method. Moreover, the color emission from blue to green can be obtained through controlling the concentration of Eu2+ and Tb3+. These results reveal the potential value of Al 5 O 6 N: Eu2+, Tb3+ phosphors as green light emitting material for near-UV pumped white light-emitting diodes. [ABSTRACT FROM AUTHOR]

• The highest energy transfer efficiency of Eu2+ → Mn2+ can achieve about 78 %. • The integrated emission intensity of Al 5 O 6 N:Eu2+, Mn2+ at 150 ℃ can maintain 82 %. • The tunable color emission of the samples can be realized tuned from blue to green. A series of Eu2+ and Mn2+ co-activated Al 5 O 6 N multi-color phosphors were fabricated through the gas-pressure sintering method, and they displayed intense blue-green emitting at near-ultraviolet irradiation due to efficient energy transfer. Dipole-dipole interaction was proved to be the leading role for Eu2+-Mn2+energy transfer and the highest energy transfer efficiency was obtained about 78 %. Furthermore, tunable emissions from blue to green were observed through regulating the concentration of Eu2+ and Mn2+. In addition, the temperature-dependent luminescence behavior of Al 5 O 6 N:Eu2+, Mn2+ was examined, and the emission intensity at 150℃ maintains 82 % of initial intensity, which indicates superior thermal stability. These outcomes illustrate that the Al 5 O 6 N: Eu2+, Mn2+ phosphors may be potentially used in white LEDs. [ABSTRACT FROM AUTHOR]