Eu3+ activated non-crystalline BaTiO3 ultra-thin film phosphor with high purity, tailored red emission from n-UV excitation for WLEDs applications

As an alternative WLED red phosphor, BaTiO3 sol-gel based ultra-thin films were doped with various mol% of Eu3+ and annealed at 500 C-degrees. The films were amorphous with short range ordered structure as seen via XRD and Raman analysis. Photoluminescence (PL) emission spectra enabled the determination of Eu3+ location asymmetry in the host via Judd-Ofelt (J-O) theory, from which Omega(2) = 9.37 x 10(-20)cm(2) and Omega(4) = 1.55 x 10(-20)cm(2) were derived, proving that the Eu3+ ions were non-centrosymmetrically located. This enhanced the Eu3+ D-5(0) -> F-7(2) electric-dipole transition at 614.0 nm with the strongest emission from 30 mol% doping. 395 nm excited intense and narrow red spectral profiles which exhibited excellent colour coordinates (x = 0.657, y = 0.342), quantum efficiency (25.7% at a film thickness of similar to 380 nm), and colour purity of (92.0%) whereby the red to orange ratio (R : O) enables colour tailoring with 5 mol% to 30 mol% Eu(3+)doping. This facilitates flexible control over the colour output, ensuring that it can be easily tailored to meet specific application requirements. The aforementioned results indicate that the red-emitting Eu3+ activated amorphous BaTiO3 ultra-thin film phosphors exhibit promising potential for application in n-UV excited WLEDs as a red phosphor with a branching ratio beta(0 -> 2) = 81.43 % making it a potential candidate for red laser materials too.