Influence of Preparation Ambient on Luminescent and Electrical Properties of TiO₂:Sm Thin Films

This study investigates the effects of different fabrication and annealing atmospheres on the properties of samarium (Sm)‐doped titanium dioxide (TiO 2 :Sm) thin films, with a focus on luminescence and electrical conductivity. TiO 2 :Sm thin films are deposited by laser ablation and annealed at 700 °C in O 2 and H 2 + N 2 atmospheres. X‐ray diffraction analysis shows that fabrication and annealing in the H 2 + N 2 atmosphere significantly inhibit crystal growth. PL spectra reveal that films fabricated and annealed in O 2 exhibit the strongest luminescence, while those in the H 2 + N 2 show quenched luminescence. X‐ray absorption fine structure results indicate that Sm 3+ ions in the non‐luminescent samples have a high‐symmetry oxygen coordination, which is unfavorable for luminescence. C – V and I – V measurements reveal a substantial increase in electrical conductivity for films fabricated and annealed in H 2 + N 2 , attributed to the incorporation of hydrogen and the formation of oxygen vacancies. This study concludes that while the fabrication and annealing in the H 2 + N 2 atmospheres enhance the electrical conductivity of TiO 2 :Sm thin films, they also degrade luminescence. Balancing luminescence intensity and electrical conductivity is crucial for the optical device application of TiO 2 :Sm thin films. It is necessary to carefully adjust the fabrication and annealing conditions to enhance electrical conductivity while maintaining strong luminescence.