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

G.R. Mamatha, B.R. Radha Krushna, J. Malleshappa, Saurabh Sharma, Sanjan Kumar, C. Krithika, Nandini Robin Nadar, Dileep Francis, K. Manjunatha, Sheng Yun Wu, H. Nagabhushana