ABSTRACTFor the evaluation of an implanted layer, photoluminescence (PL) and photoluminescence excitation (PLE) measurements, which are nondestructive and sensitive methods for identifying impurities and defects, were performed. Yb3+ -related sharp luminescence was observed at a wavelength of 1002nm, due to the transitions which occurred between the spin-orbit levels 2F5/2→2F7/2 of Yb3+ (4f13). Most efficient luminescence of Yb3+ was achieved at an excitation wavelength of around 880nm. The luminescence intensity of this peak (Yb3+) decreased with an increase in annealing temperature. Since the peak has not been observed for good samples in crystallinity, it may indicate that new, efficient energy transfer processes to rare-earth ions occur through the defect energy level. Especially, for the sample annealed at 600°C, Yb-related luminescence intensity excited by the photon energy below the band gap is about 3 times larger than that of excited by the photon energy above the band gap.