Study on luminescence properties of Ce 3+ and Eu 3+ ions in a nanocrystalline hexagonal Zn 4 Al 22 O 37 novel system.

The present communication is strongly focused on the investigation of synthesis, structural and luminescence properties of cerium (Ce 3+ )- and europium (Eu 3+ )-activated Zn 4 Al 22 O 37 phosphors. Ce 3+ - and Eu 3+ -doped Zn 4 Al 22 O 37 novel phosphors were prepared using a solution combustion synthesis route. Structural properties were studied using powder X-ray diffraction and high-resolution transverse electron microscopy. The optical properties were studied using ultraviolet-visible light spectroscopy and Fourier transform infrared spectroscopy; luminescence properties were studied using a photoluminescence (PL) technique. The crystal structure of the prepared Zn 4 Al 22 O 37 host and Ce 3+ - and Eu 3+ -activated Zn 4 Al 22 O 37 phosphors was investigated and was found to have a hexagonal structure. The measured PL emission spectrum of the Ce 3+ -doped Zn 4 Al 22 O 37 phosphor showed an intense and broad emission band centred at 421 nm under a 298 nm excitation wavelength. By contrast, the Eu 3+ -doped Zn 4 Al 22 O 37 phosphor exhibited two strong and intense emission bands at approximately 594 nm (orange) and 614 nm (red), which were monitored under 395 nm excitation. The Commission Internationale de l'Eclairage (CIE) colour coordinates of the Ce 3+ -doped Zn 4 Al 22 O 37 were investigated and found to be x = 0.1567, y = 0.0637 (blue) at 421 nm and for Eu 3+ -doped Zn 4 Al 22 O 37 were x = 0.6018, y = 0.3976 (orange) at 594 nm and x = 0.6779, y = 0.3219 (red) at 614 nm emission. The luminescence behaviour of the synthesized phosphors suggested that these phosphors may be used in lighting applications.