Photoluminescent properties of AlN: Mn2+ phosphors

White light-emitting diodes (WLEDs), which have high luminous brightness, longevity, low energy consumption and friendliness of environment, could be employed in diverse fields. Nevertheless, commercial phosphors are short of red light component. New phosphors which can emit red light are required. Mn2+ doped aluminum nitride (marked as AlN) red phosphors were prepared by a simple solid-state reaction. X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS), as well as photoluminescence (PL) spectra are utilized to characterize the prepared samples. The preparing process of AlN phosphors, phase formation and crystal structure, morphology, and photoluminescence are detailedly investigated. For Mn2+ doped AlN phosphor(marked as AlN:Mn2+), it exhibits an intense red emission caused by the 4T1(4G)-6A1(6S) transition of Mn2+. The unusual red emission of Mn2+ is ascribed to the strong nephelauxetic and crystal field between Mn2+ and the tetrahedrally coordinated N3−. The oxygen-related defects in AlN have a great influence on the photoluminescence properties of the Mn2+ doped AlN. The AlN:Mn2+ phosphors exhibits a high brightness, high color purity, and lower saturation, which make it a great candidate of red phosphors for white light-emitting diodes (WLEDs).