Used in organic light-emitting diodes (OLEDs) as a phosphorescent emitter, particularly in red or near-infrared emitting layers. Its carboxylic acid functional group allows for anchoring to metal oxide surfaces, making it suitable for dye-sensitized solar cells (DSSCs) and electrochemiluminescence (ECL) applications. Exhibits strong ECL signals when used with co-reactants like tripropylamine, useful in biosensing and immunoassays. Also employed in photochemical upconversion systems due to efficient triplet state generation. Solubility in polar solvents facilitates solution-based device fabrication.