Fullerene/cobalt porphyrin charge-transfer cocrystals: Excellent thermal stability and high mobility

Although organic semiconductors with high mobility and thermal stability are particularly desirable for practical applications, facile methods for their development still remains a big challenge. In this work, a charge-transfer cocrystal based on fullerene (C₇₀)/cobalt porphyrin supramolecular architecture was prepared by a solution-processable co-assembly strategy. This supramolecular architecture showed hole mobility as high as 4.21 cm2·V−1·s−1, and a relatively high mobility of 0.02 cm2·V−1·s−1 even after thermal treatment at 1,000 °C. Further studies confirmed the occurrence of charge-transfer from 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinato cobalt(II) (CoTMPP) to C₇₀ and the paramagnetic character within the supramolecular system. These factors were found to be responsible for the aforementioned superior performances. Thus, a novel organic semiconductor has been reported in this work, which can be potentially used for next generation electronic devices. Furthermore, it has been demonstrated that charge-transfer co-crystallization is a powerful strategy for the rational design and construction of a broad class of new multifunctional organic co-crystalline materials.