Photoluminescence optimization of Er-doped SiO2 films synthesized by radiofrequency magnetron sputtering with energetic treatments during and after deposition

By radiofrequency magnetron sputtering co-deposition we synthesized Er:SiO2 film 0.5 μm thick on silica substrates, with Er content < 0.3 atomic %. By changing the preparation condition (during deposition we have used an additional negative bias voltage applied to the substrates for inducing a low-energy ion bombardment, with or without a contemporary heating) and by varying the thermal treatment after the synthesis (the best conditions were 1 h in the range 700-800 °C, in air) we have obtained an Er:SiO2 system with an intense photoluminescence emission at λ = 1.54 μm. The best-performing Er:SiO2 samples obtained by sputtering have shown a photoluminescence response comparable to that of the typical Er:SiO2 thin film systems obtained by conventional techniques used in applicative framework.