Efficient energy transfer from Si-nanoclusters to Er ions in silica induced by substrate heating during deposition

This study investigates the influence of the deposition temperature T d on the Si-mediated excitation of Er ions within silicon-rich silicon oxide layers obtained by magnetron cosputtering. For T d exceeding 200 ° C , an efficient indirect excitation of Er ions is observed for all as-deposited samples. The photoluminescence intensity improves gradually up to a maximum at T d = 600 ° C before decreasing for higher T d values. The effects of this "growth-induced annealing" are compared to those resulting from the same thermal budget used for the "classical" approach of postdeposition annealing performed after a room temperature deposition. It is demonstrated that the former approach is highly beneficial, not only in terms of saving time but also in the fourfold enhancement of the Er photoluminescence efficiency.