Evolution of shapes and identification of level II and III features of fingerprints using CaZrO3:Sm3+ fluorescent markers prepared via solution combustion route

Abstract

Simple solution combustion route is used for the fabrication of CaZrO3: Sm3+ (1–11 mol %) nanophosphors using Aloe Vera gel as a fuel. The powder X-ray diffraction profiles confirm the pure orthorhombic phase. The granular type particles with non-uniformity in the size is observed. Photoluminescence emission spectra exhibit intense peaks at ∼571, 603, 651 and 708 nm, which are attributed to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 transitions of Sm3+ ions, respectively. The photometric properties evident that the prepared samples emit bright orange - red light with 79% color purity. The average correlated color temperature value is found to be ∼3100 K. Thermoluminescence glow curves exhibit a broad, intense peak at ∼148 °C. The highest thermoluminescence intensity is recorded for 5 mol % of Sm3+ doped sample. The thermoluminescence intensity at ∼148 °C is found to increase with increase of γ-dose. The optimized CaZrO3:Sm3+ (5 mol %) nanophosphors used as a luminescent labeling agent for visualization latent fingerprints on various porous and non-porous surfaces under ultraviolet 254 nm and normal light. The obtained results exhibits well defined ridge details with high sensitivity, selectivity, and low background hindrance which showed greater advantages. Extensive fingerprint details, namely level II and III features are clearly revealed. Hence, aforementioned results evident that the optimized sample endorse wide spread of applications, namely solid state lighting, high temperature dosimetry and advanced forensic science fields.