Used as a red phosphor in cathode ray tubes and fluorescent lamps, providing bright red emission when excited. Commonly applied in display technologies and lighting due to its sharp emission peak around 611 nm. Also utilized in anti-counterfeiting inks and security labels because of its distinct luminescence under UV light. Plays a role in bioimaging and medical assays as a luminescent probe due to long fluorescence lifetime and high sensitivity. Employed in research and industrial settings for calibration of spectroscopic equipment.