2,2 ,7,7 -Tetrakis- 9,9 -spirobifluorene

Low cost alternatives to inorganic p-type semiconductors can be found in organic species and conductive polymers. Organic hole conductors like the spiro-compound 2,2, 7,7 -tetrakis(/V,/V-di-/)-methoxyphenyl-amine)-9,9,-spirobifluorene (OMeTAD) (Fig. 17.41) have demonstrated some promise for application in dye-sensitized... 

Gratzel and co-workers reported an N3-dye-sensitized nanocrystalline Ti02 solar cell using a hole-transport material such as 2,2, 7,7 -tetrakis (N, N-di-p-methoxyphenyl-amine) 9,9 -spirobifluorene (OMeTAD) as shown in Fig. 17, as a solid electrolyte [143]. OMeTAD was spin-coated on the surface of the N3 dye/Ti02 electrode and then Au was deposited by vacuum evaporation as the counterelectrode. The cell efficiency was 0.7% under 9.4 mW/cm2 irradiation, and 3.18 mA/cm2 of Jsc was obtained under AM 1.5 (100 mW/cm2) [143]. The maximum IPCE was 33% at 520 nm. The rate for electron injection from OMeTAD into cations of N3 dyes has been estimated as 3 psec, which is faster than that of the I ion case [144]. 

Bphen 4,7-diphenyl-l,10-phenanthroline STAD 2,2, 7,7 -tetrakis-(diphenylamino)--9,9 -spirobifluorene... 

With the (+)(2-MA-2 -F-9,9 -SBF chiral aldehyde in hand, its condensation with pyrrole in classical Lindsey conditions leads to a satisfactory yield (30 %) of (+) meso-5,10,15,20-tetrakis-(2 -methylacetate-9,9 spirobifluoren-2-yl)porphyrin) (+) (MASBF)4PH2 (Scheme 12). 

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