Single-phase SrTiO 3 :mPr 3+ (m ¼ 0.01-0.1) nanoparticles have been synthesized by a hydrothermal method.Different from reported Pr 3+ -based phosphors which were all dominated by red emissions, considerably strong and overwhelming blue-green emission centered at 491 nm has been achieved together with minor green and red emissions. The absolute and relative intensities of these emissions can be modified by Pr 3+ concentrations and annealing temperatures in a controlled manner, giving rise to varied emission colors. In particular, owing to the appropriate combination of the blue to red emissions, desirable whitelight emission has been realized from the as-grown SrTiO 3 :0.01Pr 3+ and the annealed SrTiO 3 :0.06Pr 3+ samples at 350 C with CIE chromaticity coordinates of (0.33, 0.35) and (0.35, 0.37) and a correlated color temperature of 5601 K and 4883 K, respectively, indicating the promising application potential of SrTiO 3 :Pr 3+ as single-phase phosphors for white light-emitting-diodes. This work may provide a fresh route to acquire white emission from a single-composition phosphor. † Electronic supplementary information (ESI) available: Structural parameters of SrTiO 3 :mPr 3+ at room temperature rened with Pm3m space group, size distribution of the SrTiO 3 :0.06Pr 3+ nanoparticles, PLE spectra of the as-grown SrTiO 3 :0.06Pr 3+ monitored at 603 nm 617 nm and 650 nm, PL of the as-grown SrTiO 3 :0.06Pr 3+ sample under 447 nm excitation, SEM image of 1350 C annealed SrTiO 3 :0.06Pr 3+ nanoparticles, PLE spectra of as-grown and annealed SrTiO 3 :0.06Pr 3+ samples monitored at 491 nm, PLE spectra of as-grown and annealed SrTiO 3 :0.06Pr 3+ samples monitored at 617 nm, PL of the 1350 C annealed SrTiO 3 :0.06Pr 3+ sample under 490 nm excitation, CIE chromaticity diagram and chromaticity coordinates (x, y) of emission from SrTiO 3 :0.06Pr 3+ annealed at 1350 C (under 490 nm excitation), XRD patterns of as-grown and annealed SrTiO 3 :0.06Pr 3+ samples, structural parameters of as-grown and annealed SrTiO 3 :0.06Pr 3+ rened with Pm3m space group, and the energy level diagram of Pr 3+ ions. See