Synthesis of Ni2+-doped ZnAl2O4/ZnO Composite Phosphor Film with Largely Enhanced Polychromatic Emission via a Single-Source Precursor



Ni2+-doped ZnAl2O4/ZnO composite films were successfully fabricated on single crystal silicon substrates through a single-source precursor route, which mainly involved slurry coating of NiZnAl-layered double hydroxide precursor followed by calcination at elevated temperatures. Material characterization has been presented using a combination of X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, Raman spectra, UV–vis diffuse reflectance spectra, and fluorescence spectroscopy measurements. The results showed that Ni2+ ions could be uniformly doped in the two-phase ZnO and ZnAl2O4 lattices. A broadened and intense polychromatic emission peak covering the whole visible region was obtained over 4.3 mol% Ni2+-doped ZnAl2O4/ZnO composite film, which was attributed to the presence of an appropriate number of luminescent Ni2+centers in the ZnO and ZnAl2O4 double host matrix, thus largely enhancing the related transition. We believe that such unique ZnAl2O4/ZnO films can open up a new opportunity for advanced applications of composite phosphors.