Influence of Yb3+ doping concentration on upconversion luminescence of Er3+ in Lu2O3 phosphor

Cubic phase Lu2O3:Er3+/Yb3+ nanocrystal phosphors were prepared by sol–gel method. Fourier transform infrared (FT-IR) spectra were measured to evaluate the vibrational feature of the samples. Green and red radiations were observed upon 980 nm diode laser excitation. Laser power and Er3+ or Yb3+ doping concentration dependence of upconversion luminescence were studied to understand upconversion mechanisms. Excited state absorption, cross relaxation and energy transfer processes are the possible mechanisms for the visible emissions.