Flame aerosol deposition of Y₂O₃:Eu nanophosphor screens and their photoluminescent performance

Abstract

Screens of Y 2 O 3 :Eu 3+ -nanophosphor (d BET = 24 nm) with coating densities in the range 0.23-3.8 mg cm -2 were obtained by flame aerosol deposition (FAD) from nitrate-based precursors. The average deposition rate was 0.22 mg cm -2 min -1 . Porosity of the obtained deposits was 0.973 0.004. Light scattering of the coatings in the visible range showed a Rayleigh-like dependence on wavelength and, in comparison to the screens made of the commercial micrometer-sized phosphor powder (d SEM = 4 m), was reduced by up to two orders of magnitude. As a result, the nanophosphor coatings maintained nearly constant brightness in a very wide range of coating densities. Furthermore, it should be expected that a substantially improved screen resolution can be achieved with such screens. For excitation at a wavelength of 254 nm, the maximum brightness of the FAD-deposited (Y 0.92 Eu 0.08 ) 2 O 3 phosphor screens in the transmission mode was nearly one third of that of the screens made of the commercial phosphor. It was demonstrated that light reflection from the supporting substrate and porosity of the coating significantly influence its photoluminescent performance.