Investigating the influence of mono-, di-, and trivalent co-dopants (Li+, Na+, K+, Ca2+, Bi3+) on the photoluminescent properties and their prospective role in data security applications for SrAl2O4:Tb3+ nanophosphors synthesized via an eco-friendly combustion method

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 299; p. 117008
• Main Authors: Mamatha, G.R, Radha Krushna, B.R, Malleshappa, J., Sharma, S.C., Kumar, Satish, Krithika, C., Robin Nadar, Nandini, Francis, Dileep, Manjunatha, K., Yun Wu, Sheng, Nagabhushana, H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2024
• Subjects: Co-dopants; Flexible films; Latent finger prints; Photo-stability; Photoluminescence; Co-dopants; Photo-stability; Latent finger prints; Photoluminescence; Flexible films
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2023.117008

[Display omitted] •Green emitting SrAl2O4:Tb3+ (1–5 mol %) phosphor is synthesized via green combustion route.•Upon excitation with a 377 nm wavelength, the emission spectra in green display strong major peaks at 480, 541, 587, and 620 nm.•A platform based on photoluminescence has been set up for in-situ visualization of latent fingerprints using the powder dusting method.•Superior contrast, sensitivity, selectivity, and low background impediment are displayed by developed latent fingerprints.•The SrAl2O4:4Tb3+/Li+ phosphor may find use in the environment and bio-medical industries. Nanostructured SrAl2O4:Tb3+/M (M = Li+, Na+, K+, Ca2+, Bi3+) green nanophosphors (NPs) were synthesized through an environmentally friendly combustion process, employing Areca nut (A.N) as a sustainable fuel source. Alkali metal co-dopants were introduced to optimize luminescent intensity and assess their suitability for data security applications. Photoluminescence (PL) intensity increased with rising Tb3+ concentrations (1–5 mol %) until reaching a maximum at 3 mol %, after which quenching occurred. The phenomenon of Tb3+ concentration quenching at 3 mol % was explained using the Van Uitert equation, which accounts for dipole–dipole interactions. To enhance luminescence efficiency, various metal ions, including Li+, Na+, K+, Ca2+, and Bi3+, were explored. Notably, SrAl2O4:Tb3+ (SAO:Tb3+) co-doped with Li+ ions exhibited the highest PL intensity, surpassing that of Tb3+ by a factor of 41. The estimated CIE value for green emission are x  = 0.3541 and y = 0.5562. It is observed that the CIE coordinates of Tb3+ activated SAO NPs are situated in the green region. The CCT value of SAO:Tb3+/Li+ was found to be 5117 K, which is useful for cool LEDs. The Li+ doped samples proved exceptionally effective in latent fingerprints (LFPs) detection, revealing level I-III ridge features crucial for personal identification. Under NUV light, the PDMS wrapping of the SAO:Tb3+/Li+ NPs accomplished a green glow. Based on the results, SAO:Tb3+/Li+ green-emitting phosphors is a promising material for white LEDs, optical temperature sensors, and flexible display applications. This comprehensive study underscores the outstanding multifunctional potential of Li+ co-dopants among the various ions considered.