Published online by Cambridge University Press: 19 November 2013
Structural, optical and luminescent properties of Si-rich HfO2 films fabricated by RF magnetron sputtering were investigated versus annealing treatment. Pronounced phase separation process occurred at 950-1100°C and resulted in the formation of hafnia and silica phases, as well as pure silicon clusters. An intense light emission of annealed samples in visible spectral range was obtained under broad band excitation. It was ascribed to exciton recombination inside silicon clusters as well as host defects. To confirm the formation of Si clusters, the structures were co-doped with Er3+ ions and effective light emission at 1.54µm was obtained under non-resonant excitation due to energy transfer from Si clusters towards Er3+ ions. The interaction of Si clusters, host defects and Er3+ ions under is discussed.