Used as a hole-transporting material in organic light-emitting diodes (OLEDs) and perovskite solar cells due to its high hole mobility and excellent thermal stability. It helps improve device efficiency by facilitating the transport of positive charges from the anode to the emissive layer. Commonly found in multilayer thin-film structures where reliable charge transport and film uniformity are critical. Also employed in photorefractive materials and electrochromic devices because of its strong amorphous film-forming ability and reversible oxidation properties.