2D-BCNO with Eu3+: partial energy transfer and direct natural white light for LEDs

2D-BCNO is a promising candidate as a new phosphor for solid state lighting applications with many advantages, but lacks the emission in the red region of the spectrum much needed for white LEDs. As an attempt to overcome this barrier, BCNO sheets incorporated with red emitting Eu3+ ions were synthesized via a facile combustion method. The broad emission from BCNO in its free form was extended by the addition of sharp red emission from Eu3+ to generate white light directly under UV excitation. Good quality natural white light emission was achieved with the optimum concentration of Eu3+ being 0.05–0.07 mole% and its application for white LEDs was demonstrated. Further studies on the photoluminescence behaviour revealed a partial energy transfer from BCNO to Eu3+, which played a major role in generating the white light as illustrated with the help of a modified band level diagram.