Transition-metal activated phosphors are an important family of luminescent materials that can produce white light with an outstanding color rendering index and correlated color temperature for use in light-emitting diodes. In recent years, work in this quite “hot” research field has focused on the development of Mn²⁺ and Mn⁴⁺ activated red phosphors. In this review article, we provide an overview of recent studies on Mn²⁺ and Mn⁴⁺ doped phosphors, including detailed synthesis routes (solid-state reaction and wet-chemical synthesis) and description of luminescence mechanisms and phosphors’ behaviors; discuss their promising applications in white light-emitting diodes; and present an extensive list of references to representative works in this field.

A single-phased K ₃ ZrF ₇ :Mn ⁴⁺ has been successfully synthesized, in which Mn ⁴⁺ playing as the luminescent center to absorb blue light and emit red light. Obvious warm white light can be observed from the WLED based on this red phosphor.

New red-emitting phosphors A₂HfF₆(A = Rb⁺, Cs⁺) doped with Mn⁴⁺located at the center of a regular octahedron show intense red emission under blue light excitation and find potential application in LED chips.

The red Cs ₂ NaAl ₃ F ₁₂ :Mn ⁴⁺ phosphor with intense ZPL emission was obtained via the occupation of Mn ⁴⁺ for Al ³⁺ , indicating its high colour purity and potential use in WLEDs.