The influence of Zr4+ doping on the structural and photoluminescence properties of LaPO4:Ce3+/Mn2+ phosphors

A series of LaPO4:Ce3+/Mn2+/xZr4+ (LPOCM:xZr4+) (0% ≤ x ≤ 30%) emission-tunable phosphors were synthesized by a cost-efficient co-precipitation method. The samples presented a monoclinic phase structure and a macroscopic rod-like shape. Photoluminescence (PL) and electron paramagnetic resonance spectroscopy were employed, the Zr4+ concentration-dependent excitation, emission, decay time, and energy transfer (Ce3+ → Mn2+) being discussed in detail. Under UV-excitation of Ce3+, typical green-red PL emission is observed for the LPOCM:xZr4+ phosphors, which is attributed to the 4T1(G) → 6A1(S) transition of the Mn2+ ion. The charge compensation strategy achieved the Mn2+ PL-enhancement and color-tuning effect in LPOCM:xZr4+ phosphors. A strong blue emission with color purity of up to 97% is observed in the Ce3+ singly-doped sample. Cold white light emission can be obtained by doping 5% Zr4+ in LPOCM phosphor under UV irradiation. The corresponding CIE 1931 coordinates were inferred to be (0.309, 0.329), close to the standard white emission (0.330, 0.330). The color was tuned towards whitish-orange/red emissions for higher Zr4+ concentrations (15% and 30%). These findings indicate that the charge compensation approach can greatly improve the PL and color-tunable properties of LPOCM:xZr4+ phosphors. [Display omitted] •LPOCM:xZr4+ (x = 0, 2, 5, 15, and 30%) phosphors have been synthesized by the co-precipitation method.•Zr4+ addition has an evident effect on structural, EPR and luminescence properties of LPOCM phosphors.•Green-red emissions were observed due to an energy transfer from Ce3+-donor to Mn2+-acceptor.•The Mn2+-PL signal in LPOCM:xZr4+ phosphors was enhanced via a charge compensation strategy.•The emitted light color of LPOCM was tuned from blue to white and finally to whitish-orange/red by tuning the Zr4+ amount.