Tetra-N-phenylbenzidine (TPB) is widely used in the field of organic electronics, particularly in the development of organic light-emitting diodes (OLEDs). It serves as a hole-transport material, facilitating the efficient movement of positive charges within the device, which enhances overall performance and energy efficiency. TPB is also employed in the fabrication of photovoltaic cells, where it aids in improving charge separation and transport, contributing to higher power conversion efficiencies. Additionally, its application extends to organic thin-film transistors (OTFTs), where it acts as a semiconducting layer, ensuring stable and reliable operation. The compound's ability to form stable films and its favorable electronic properties make it a valuable component in advanced optoelectronic devices.