Spiro-OMeTAD Hole Transport Material for solid-state Dye Solar Cells and Perovskite Solar Cells. SOLARONIX Chemical Name : 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene Molecular Formula :C81H68N4O8 Formula Weight :1225.43 g/mol CAS Number : 207739-72-8 Aspect : white to beige powder