Optoelectronic Properties of a Fullerene Derivative Containing Adamantane Group

A fullerene derivative linked with an adamantane cage, [6,6]-phenyl-C61-butyric acid 1-adamantane methyl ester (PC61BAd), has been designed and synthesized. Systematic investigations on its organic field effect performance, photovoltaic properties, and corresponding thermal stability have been made. In OFET device, the electron mobility (μe) of PC61BAd was found to reach a value as high as 0.01 cm(2)/V·s with a high on-off (Ion/Ioff) ratio of 4.9 × 10(6) that is useful for logic device applications. In the organic photovoltaic devices of P3HT:PC61BAd, the power conversion efficiency (PCE) was found to reach 3.31 % in the optimized device. More importantly, the active layer of P3HT:PC61BAd was found to exhibit superior thermal stability over that of P3HT:PC61BM. After heating at 150 °C for 20 h, the P3HT:PC61BAd device still showed a PCE of 2.44 %, demonstrating the applicability of PC61BAd as an acceptor material for the preparation of thermally stable organic solar cells. X-ray diffraction and atomic force microscopy were employed to probe the structure and morphology of PC61BAd and to rationalize its performance as an organic electronic material.