Generation of white light from oxy-fluoride nano-glass doped with Ho3+, Tm3+ and Yb3+

Thermal treatment at 480 °C for 40 h resulted in the precipitation of β-PbF2 nano-crystals inside the oxy-fluoride glasses co-doped with Ho3+, Tm3+ and Yb3+. Generation of white light was achieved through the simultaneous blue, green and red up-converted emissions by pumping at 900 nm. Simulation of sunlight was most successfully achieved with pump power of ∼ 150 mW.