Used as a key intermediate in the synthesis of high-performance organic semiconductors and optoelectronic materials. Its rigid spirobifluorene backbone enhances thermal stability and prevents crystallization in thin films, making it ideal for OLEDs and perovskite solar cells. The bromine sites allow for further functionalization via cross-coupling reactions, enabling tailored electronic properties in conjugated polymers and small molecules for efficient charge transport. Commonly employed in hole-transport materials and host compounds in emissive layers due to its high triplet energy and good morphological stability.