<p>The phosphor-converted white light-emitting diodes (w-LEDs) are considered a promising replacement for traditional light sources in the lighting industry. This work employed a high-temperature solid-state reaction to synthesize a novel series of single-component Ca₈SrLa(PO₄)₇:Eu²⁺,Mn²⁺ (CSLP:Eu²⁺,Mn²⁺) phosphors with tunable emission properties, and the phase and crystal structures of CSLP:Eu²⁺,Mn²⁺ were characterized. The Eu²⁺-activated phosphors are highly responsive to excitation by ultraviolet (UV) light in the 250- to 400-&#xa0;nm range and emit a strong green emission with the peak at about 510&#xa0;nm. By co-doping Eu²⁺ and Mn²⁺ ions into the CSLP matrix, the relative intensities of the green and red emissions, which come from the Eu²⁺ and Mn²⁺ respectively, can be adjusted by changing the Mn²⁺ concentration. The emission color shifts from green to warm white as the Mn²⁺ concentration increases. By means of decay lifetime measurements and photoluminescence analysis, the energy transfer process from Eu²⁺ to Mn²⁺ in the CSLP:Eu²⁺,Mn²⁺ compound gas been comprehensively investigated, and it has been demonstrated that the energy transfer is mediated by a dipole–quadrupole mechanism. The CIE coordinates and thermal stability of CSLP:Eu²⁺,Mn²⁺ were further studied, and the results suggest that CSLP:Eu²⁺,Mn²⁺ phosphors hold significant potential for use as UV-convertible phosphors in w-LEDs.</p>