The effective fingerprint detection application using Gd2Ti2O7:Eu3+ nanophosphors

Abstract Nanostructure phosphors have been used for optical device and identification of individual fingerprint information. Herein, we report the orange-red emitting Eu 3+ ions activated cubic Gd 2 Ti 2 O 7 nanophosphors through a citrate sol-gel method. The crystal structure, morphology, optical band gap, luminescent properties, Judd-Ofelt and fingerprint were analyzed. The crystal structure of Gd 2 Ti 2 O 7 :Eu 3+ nanophosphors confirmed the cubic phase. The morphology of nanophosphors exhibited the irregular particle shape with tens-nanometer size. The PL intensity was increased with rising Eu 3+ ion concentration, indicating an optimum concentration of 0.09 mol. The emission spectra appeared an orange-red emission ( 5 D 0 → 7 F 1 ) with the CIE coordinates of (x = 0.615, y = 0.384). The latent fingerprints developed on various substrate have been exhibited excellent visualization and sensitivity. Based on these results, Gd 2 Ti 2 O 7 :Eu 3+ nanophosphors are promising applications such as luminescent materials for luminescent devices and latent fingerprint.