Blue and bluish-white colors from the luminescent ZrO₂ and ZrO₂: Al³⁺ films prepared by the USP method

ZrO2 and ZrO2: Al3+(x at.%) films were deposited by ultrasonic spray pyrolysis process. Luminescent films were produced from Oxychloride Zirconium Octahydrate and Aluminium Chloride Hexahydrate as precursors. Measurements of photo and cathodoluminescence were carried out doing variations on deposition temperature and doping concentration (x at.% Al(3+)ions). With the increase in substrate temperature, an overall growth of photo-cathodoluminescence intensities was perceived. Furthermore, these films presented luminescence concentration quenching with hight Al doping concentration. Chromaticity coordinates indicated blue emission from host lattice (ZrO2 films) and cold-white emissions from ZrO2: Al3+(x at.%) films. Closest CIE coordinates to the perfect white emission were x = 0.303, y = 0.337. XRD patterns, measured with variations of substrate temperature, showed tetragonal phase of nano-zirconium oxide films. In addition, surface morphology characteristics for studied films are presented.