Synthesis of an All-in-One Molecule (for Organic Solar Cells)

A multidomain compound with applications in the area of organic solar cells has been prepared. This all-in-one molecule compound integrates all the functionalities needed for solar cell action from light harvesting, carrier generation, and separation, to transport and contact to external electrodes. A convergent synthetic strategy with some 60 steps involving preparation of regioregular oligothiophenes, a zinc porphyrin, a bisterpyridine ruthenium(II) complex, a hetero oligo phenylenevinylene and functional end groups is described. Preliminary investigations of photovoltaic devices based on the target molecule gave values of 0.18 V, 0.0044 mA cm(-2), 29% and 0.000081% for the open circuit voltage (Voc), short circuit current (Isc), fill factor (FF), and efficiency (eta). These poor values are compared to those obtained with an oligo-3-hexylthiophene which gave values of 0.7 V, 0.046 mA cm(-2), 24.6%, and 0.0081% for the open circuit voltage (Voc), short circuit current (Isc), fill factor (FF) and efficiency (eta). This latter compound was also studied in a bulk heterojunction device with PCBM (1:1 blend) which gave values of 0.43 V, 0.45 mA cm(-2), 33.5%, and 0.063%.