Electronic and optical properties of a novel fluoroaluminate red phosphor Cs2NaAl3F12:Mn4+ with high color purity for white light-emitting diodes

Abstract

In this work, a novel fluoroaluminate red phosphor of Cs₂NaAl₃F₁₂:Mn⁴⁺ with excellent color purity was fabricated via the introduction of Mn⁴⁺ in the octahedral center. The crystal and electronic structures, luminescence properties and optical performances were characterized and investigated in detail. The evidences showed that Cs₂NaAl₃F₁₂:Mn⁴⁺ well-crystallized into a single phase with particulate morphology, and the non-equivalent occupation in Cs₂NaAl₃F₁₂ resulted in sharp red emissions with improved color purity upon blue light illumination. For solid-state lighting, the optical parameters consisted of the “blue-yellow-red” contributions significantly improved to a high color-rendering index of 88.7 and a low color temperature of 3856 K, indicating the potential use of Cs₂NaAl₃F₁₂:Mn⁴⁺ for warm white light-emitting diode applications.