Highly efficient and self-activating Zn3V2O8 phosphor for the fabrication of cool-white light emitting devices

Abstract

Achieving an ideal white light with eco-friendly phosphor material with a high quantum efficiency (QE) together with an appreciable correlated color temperature (CCT) and color rendering index (CRI) is considered as a global challenge. To address the issue, we have fabricated a self-activated Zn3V2O8 phosphor-based white light emitting device (WLED) as single emitting compound with desired CCT and color purity values of ∼5074 K and 10.47 × 10−2 respectively, using a moderately low temperature assisted solid-state reaction process carefully ruled out the presence of rare-earth ions. The prepared Zn3V2O8 phosphor exhibited a highly visible yellow (575 nm) photoluminescence (PL) induced by the 3T2 (t152e) →1A1 and 3T1(t152e) →1A1 (t16) transitions of vanadate [VO4]3-, which unveil a significant QE of 67%. The temperature-dependent PL spectra showed a high thermal stability and CIE color coordinates (0.45, 0.47), falling in the exact yellow region. The combination of Zn3V2O8 phosphor and deep blue (405 nm, 40 mW) emission from LED resulted in white light emission with CIE color coordinates and CRI of (0.33, 0.36) and 93, respectively. This work shows that the newly exposed broadband yellow-emitting Zn3V2O8 phosphors as a potential candidate for phosphor-converted WLEDs with high color quality via a non-rare-earth activation approach.