Eu 3+ -Activated Sr 3 ZnTa 2 O 9 single-component white light phosphors: Emission intensity enhancement and color rendering improvement

Abstract

Single-component white light phosphors with a broad and full color spectrum are urgently required to overcome residual problems with commercial phosphors. In this paper, we describe how Eu 3+ , as the dopant of Sr 3 ZnTa 2 O 9 (SZT), plays an important role in structural modulation (including structural order-disorder and intrinsic oxygen defects), as demonstrated by electronic structural calculations and systematic experiments. Furthermore, 5 D 0 → 7 F 2 emission of Eu 3+ provides the red component of the emission spectrum and increases the color rendering index of SZT:Eu 3+ phosphors. Consequently, the resulting phosphor SZT:10%Eu 3+ shows significantly enhanced emission intensity, and its broadband emission covers the entire visible region from 400 nm to 720 nm. A fabricated LED device using a near-ultraviolet 370 nm chip coated with a single-component, the SZT:10%Eu 3+ phosphor, shows warm white emission with a high color rendering index (R a = 82).