Tunable luminescence from Bi sensitized La Zr O :Eu red nanophosphors for display applications.

Bismuth ion (Bi ) sensitized, europium ion (Eu ) activated La Zr O nanophosphors are prepared successfully by simple wet chemical method. Strong blue emission of singly doped La Zr O with Bi was observed at 310 nm excitation, its wide emission spectrum has a peak maximum at 465 nm ascribed to electronic transition P  →  S of Bi . The recorded photoluminescence spectra of y at% Eu codoped La Zr O , when excited at 285 nm, the emission spectrum exhibits maximum peaks at wavelength values 615 nm, 646 nm and 665 nm which are ascribed to D  →  F , D  →  F and D  →  F transitions of Eu respectively. The chromaticity coordinates for the optimized sample were found to be (0.519, 0.329). Sensitizing with Bi can affect the luminescence properties of La Zr O :Eu phosphors. With reference to the change in Eu concentration from Y  = 1, 2, 3, 4 and 5%, color tunable luminescence from blue to orange, red of La Zr O :Bi ,Eu phosphors are observed. The lifetime decay values, energy level description and CIE chromatic color coordinates for Bi , Eu in La Zr O :Bi ,Eu codoped sample was discussed. The spectral overlap between sensitizer, activator ions confirms the efficient energy transfer from Bi to Eu in La Zr O :Bi ,Eu codoped sample and is via a dipole-quadruple mechanism.