Eu3+-doped SiO2-Y2O3 containing Sr2+ for application as fingerprinting detector

The use of photoluminescent materials in forensic science is essential for the development of systems that improve the final quality of images, so the results provided by security institutions can be more accurate. Thus, the utilization of trivalent Rare Earth ions (RE3+) doped materials, in this case the Eu3+ ion, is interesting, since it has a lifetime on the ms scale and an intense emission with a monochromatic character in the red region. Furthermore, materials with red emission with applications in the forensic area are rare and financially expensive. Because of that, luminescent materials based on SiO2-Y2O3:Eu3+, Sr2+ represent an alternative more accessible to current photonic materials for application in the field of forensic investigation. Intense photoluminescence in the visible red region of the material obtained in this work was observed, both in the isolated material and impregnated in the digital printing present on the surface of a glass slide. The isolated material presented a lifetime between 1.65 and 1.78 ms, with results of structural microdeformation and network parameters that did not significantly influence the properties of the system, showing its robustness before and after its application on the fingerprint. Even coated on fingerprints, the materials showed intense emission and monochrome character in the red region assigned to the thin emission band positioned around 612 nm. The projections of the sublevels of the 7F1 crystal field level calculus performed by the method of equivalent nearest neighbors (MENN) do not show significant changes for this system. In summary, this work shows characteristics that are of paramount importance to obtain images with a higher resolution of latent fingerprints for possible forensic applications with higher robustness during applications.

Automated summary

This study utilized luminescent materials with red emission characteristics, showing strong photoluminescence both in isolated material and impregnated in digital prints, which are essential for obtaining higher resolution images of latent fingerprints.