Effective fingerprint recognition technique using doped yttrium aluminate nano phosphor material.

First time the yttrium aluminate nanoparticles are used to improve the fingerprint quality. Eco-friendly green combustion process is used to synthesize YAlO3:Sm(3+) (0.5-11mol%) nanophosphor using green tea leaf extract as non-toxic and eco-friendly fuel. Powder X-ray diffraction study confirms the orthorhombic phase. The average sizes of the crystallites were found to be in the range 20-35nm. The emission peaks centered at 564, 601 and 647nm is attributed to 4f-4f (4)G5/2→(6)HJ=5/2,7/2,9/2 forbidden transitions of Sm(3+) ions. Judd-Ofelt theory is applied to experimental data for providing qualitative support by determining J-O intensity parameters. The Commission International De I-Eclairage chromaticity co-ordinates are very close to National Television System Committee standard value of white emission (x=0.296, y=0.237). Further, correlated color temperature is found to be ∼11,900K. A simple, fast, highly sensitive and low-cost method for the detection and enhancement of fingermarks in a broad range of surfaces is developed and constitutes an alternative to traditional luminescent powders.