Color tunable green-yellow-orange-red Er3+/Eu3+-codoped PbGeO3:PbF2:CdF2 glass phosphor for application in white-LED technology

Color tunable wide gamut light covering the greenish, yellow-green, yellow, orange, and reddish tone chromaticity region in Er3+/Eu3+-codoped lead-cadmium-germanate PbGeO3:PbF2:CdF2 glass phosphor is presented. The phosphors were synthesized, and their light emission properties examined under UV and blue LED excitation. Luminescence emission around 525, 550, 590, 610, and 660 nm was obtained and analyzed as a function of Eu/Er concentration, excitation wavelength, and glass host composition. The color tunability was actually obtained via proper combination of Er3+ and Eu3+ active ions concentration. The combination of the emission tone with blue LEDs in the region of 400-460 nm, yielded a mixture of light with color in the white-light region presenting a color correlated temperature in the range of 2000-4000 K. Results indicate that the color-tunable fluorolead germanate erbium/europium co-doped glass phosphor herein reported is a promising novel contender for application in LED-based solid-state illumination technology