Solution-processable fullerene derivatives for organic photovoltaics and n-type thin-film transistors

Two solution-processable fullerene derivatives (C60TH-Hx and C60TH-Hx-a) were successfully synthesized for organic photovoltaics and n-type thin-film transistors. The best power conversion efficiency (PCE) was observed in a layered structure of P3HT:C60TH-Hx (PCE = 2.44%), which slightly exceeded that of P3HT:PCBM (PCE = 2.39%). We found a very low PCE for P3HT:C60TH-Hx-a (similar to 0.14%) due to the poor solubility of C60TH-Hx-a. In addition, n-type thin-film transistors were fabricated by solution-processing techniques. The measured values of electron mobility in the devices for PCBM, C60TH-Hx, and C60TH-Hx-a were 5.8 x 10(-3), 2.5 x 10(-2), and 8.5 x 10(-4) cm(2) V-1 s(-1), respectively. (C) 2011 Elsevier B. V. All rights reserved.