Red emitting Ca ₂ MgWO ₆ :Eu ³⁺ phosphor for latent finger and lip prints detection

Abstract A red-emitting Ca 2 MgWO 6 :9 mol% Eu 3+ (CMW-9) was synthesized via flux-assisted high-temperature solid-state reaction to determine its effectiveness as a luminescent material for forensic detection and high-resolution visualization of latent fingerprints and lip prints on various surfaces. The structural, optical, and morphological properties of the material were investigated. The XPS spectra confirm the chemical and electronic states, as well as the binding energy of the phosphor. The x-ray diffraction confirms the formation of a single-phase double perovskite structure. Upon 467 nm excitation, the CMW-9 exhibits strong red emission at 616 nm, favorable for latent fingerprint and lip print development and visualization. CMW-9 demonstrated high efficiency in revealing level 1–3 latent fingermark details on non-porous surfaces, such as glass, and on challenging surfaces, including painted materials, as well as level 1–2 features on semi-porous surfaces like plastics. The phosphor enabled high-resolution visualization and 3D topographical analysis of latent lip prints on non-porous and semi-porous surfaces, revealing distinct regional ridge patterns. These findings suggest CMW-9 as a promising red-emitting luminescent material for forensic detection of latent prints.