Used as a precursor in the synthesis of luminescent materials, particularly in the production of red phosphors for LED lighting and display technologies. Commonly employed in the fabrication of fluorescent labels for bioimaging and immunoassays due to its strong red emission under UV light. Also utilized in the development of security inks and anti-counterfeiting tags because of its distinct luminescent signature. Plays a role in doping glass and ceramics for optical applications, including lasers and optical amplifiers.