Er3 +/Sm3 +- and Tb3 +/Sm3 +-doped glass phosphors for application in warm white light-emitting diode

•Tunable polychromatic light with low CCT•Application in warm white light emitting diode•New samarium/erbium and samarium/terbium co-doped lead–cadmium–germanate glass phosphors

Tunable polychromatic light emission within the low correlated color temperature range was produced using terbium- and/or erbium–samarium co-doped PbGeO3:PbF2:CdF2 glass phosphor. The phosphors were synthesized, and their luminescence characteristics were examined under UV–blue light-emitting-diode laser excitation. Luminescence emissions around 490, 545, 600, and 645 nm in Tb3 +/Sm3 + co-doped phosphor and 525, 545, 600, and 645 nm in Er3 +/Sm3 + co-doped phosphor were obtained and analyzed as a function of the active ion concentration and excitation wavelength. Color tunability in the red–orange–yellow–green region was achieved combining the Tb3 +, Er3 +, and Sm3 + active ion contents. Results suggest that the color-tunable polychromatic light emitter herein reported is a promising candidate for application in warm white-light emission.