Latent Fingerprint Imaging Using Dy and Sm Codoped HfO₂ Nanophosphors: Structure and Luminescence Properties

Abstract

The development of latent fingerprints (LFPs) detected at the site of crime is considered as an imperative physical evidence in forensic investigations. Herein, a rapid and cost‐effective approach using nonhazardous Dy and Sm codoped HfO2 nanophosphors is demonstrated to be utilized for LFP imaging. Sol–gel method can produce Dy and Sm codoped HfO2 of monoclinic phase with crystallite size ranging from ≈10 to 25 nm. While selected area electron diffraction and lattice spacing calculated from high‐resolution transmission electron microscopy confirm monoclinic phase, Le‐Bail profile refinement of X‐ray diffraction (XRD) patterns demonstrate an exponential increase in lattice volume with incorporating various concentrations of Dy and Sm in HfO2 lattice. Exciting Dy and Sm codoped HfO2 with 393 nm photoluminescence spectra show emissions in blue, yellow, and near red regions emerging primarily due to energy transfer from Dy3+ to Sm3+ through multipolar interaction suggested by time resolved decay spectra. Combining excitation and emission spectra, an energy band diagram is proposed. Owing to excellent emissions, Dy and Sm codoped HfO2 are explored for LFP imaging with good selectivity and resolution over multivariate surfaces like float glass and aluminum foil. The third‐level details like enclosure and termination–bifurcation are extracted due to nanosized nature of particles.

Resistive Switching Characteristics of HfO2 Thin Films on Mica Substrates Prepared by Sol-Gel Process

“…Figure 3 indicates the GIXRD patterns of the HfO 2 films grown on two different devices. As can be seen from Figure 3, the HfO 2 thin films had high crystallinity—a polycrystalline (100), (110), ( 1 11), (111), (200), and (220) oriented monoclinic phase structure [24,25]. Additionally, the PDF#78-0050 of the HfO 2 monoclinic phase is inserted in Figure 3 to better identify the XRD peak of the HfO 2 film.…”

Stabilization of Cubic Phase at Room Temperature and Photoluminescence Properties of Dy and Sm Co-Doped HfO2 Nanoparticles

“…0D0S exhibits distinguished diffraction peaks such as (011), ( 110), ( ) 111 , (111), ( 020), ( 200), ( 021), ( ) 211 and (112) attributed to the monoclinic phase of HfO 2 , space group, P2 1 /c. 18 At low Sm and Dy concentration i.e. in case of 0.5D0.5S, the diffraction peaks become significantly broad distinctive to decrease in the crystallite size and the position of peaks remains same suggesting that the sample preserves monoclinic phase.…”

Spectroscopic characterization of Er,Yb:Y2Ti2O7 phosphor for latent fingerprint detection

“…Lanthanide ions are usually considered biocompatible materials, especially Er 3+ , Eu 3+ , Gd 3+ , Sm 3+ ,Yb 3+ and Y 3+ ions which are found to have a relatively low toxicity [20][21][22][23]. Many works focus on rare earth ion doped luminescence materials because of the peculiar optical properties arising from the intra 4f transitions.…”