Optical properties of transparent wavelength-conversion film prepared from YVO₄: Bi³⁺, Eu³⁺ nanophosphors

The optical properties of the transparent wavelength-conversion film containing 38.8 wt % YVO₄: Bi3+, Eu3+ nanoparticles of 10.8±1.6 nm in size are compared to that of the film containing 30.0 wt % micron-sized particles of 1.12±0.48 μm in size. The photoluminescence intensity at 619 nm corresponding to the f-f transition of Eu3+ for the film containing nanoparticles increases with increasing the film thickness up to 400 μm, whereas that of the film containing micron-sized particles reaches the maximum at the film thickness of ∼40 μm. The transmittance at 619 nm for the former is ∼96% irrespective of the film thickness, whereas that is less than 0.17% for the latter. These results suggest that the transparent film of YVO₄: Bi³⁺, Eu³⁺ nanoparticles has markedly low light-scattering loss.