Tuning the morphology of Mg2TiO4: Mn4+ for luminescence performance and latent fingerprint visualization

Mn4+ doped Mg2TiO4 samples were prepared through a solvothermal calcination method. The samples with hollow sphere structure about 400 nm were obtained using a hard template, and the uniform size distribution could be realized by prolonging the aging time. Compared with the solid sphere sample, the Mn4+ doped Mg2TiO4 samples with hollow sphere structure exhibited excellent luminescence performance owing to the boosted radiation light. Simultaneously, the hollow sphere structure with the loose shell could also make the luminescence intensity of Mg2TiO4: Mn4+ improved by reducing the light scattering on the exterior of sphere and enhancing the reflecting in interior of sphere. By the virtues of their strong emission intensities, the samples are applied to visualize the potential fingerprints on the glass surfaces. Under UV light, the pattern and ridge flow of the fingerprint are clearly identified. More importantly, we demonstrated that the Mn4+ doped Mg2TiO4 samples with hollow sphere structure are highly sensitivity in identifying three-level features of fingerprint, such as pores and scars. The advantages for light intensity and resolution of fingerprint images coated with the Mg2TiO4: Mn4+ samples give it potential application in the field of latent fingerprint identification.