Diphenyliodonium trifluoromethanesulfonate is widely used as a photoacid generator in photoresist formulations for the semiconductor industry. It plays a critical role in the photolithography process, where it generates strong acids upon exposure to UV light, facilitating the patterning of microelectronic components. Additionally, it is employed in the synthesis of organic compounds, particularly in cationic polymerization reactions, where it acts as an efficient initiator. Its strong oxidizing properties also make it useful in various organic transformations, including cross-coupling reactions and the functionalization of aromatic compounds. In advanced materials science, it is utilized to modify surfaces and create thin films with specific properties.