Effect of erbium fluoride doping on the photoluminescence of SiOx films

The photoluminescence of SiO x films deposited on c -Si wafers by the thermal evaporation of SiO in a vacuum and, for the first time, doped with ErF 3 by coevaporation is studied. It is shown that, like undoped SiO x films, the unannealed SiO x :ErF 3 films passivate the surface of the Si wafers and, thus, increase their edge photoluminescence intensity almost fivefold. A similar increase is observed after annealing of the doped films in air at 750°C. Doping with ErF 3 suppresses the photoluminescence of Si nanoclusters, if the films have been subjected to high-temperature annealing (at 750°C). In this case, the PL intensity of the band with a peak at ∼890 nm decreases as well. The ∼890 nm band is observed for the first time and, due to its features, is attributed to transitions in SiO x matrix defects. The experimentally observed effect of ErF 3 doping on SiO x film photoluminescence is interpreted. An intense photoluminescence signal from Er 3+ ions in the nearinfrared spectral region (the 4 I 11/2 → 4 I 15/2 and 4 I 13/2 → 4 I 15/2 transitions) is observed in the SiO x :ErF 3 films annealed in air at 750°C. This finding shows that 1.54 μm luminescent emitters, which are currently in popular demand, can be produced by a simple low-cost method.