A desirable vertical phase separation of a bulk-heterojunction was achieved by inserting a P3HT layer between the blend layer and the poly(3,4- ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) layer. According to the high (PEDOT:PSS) and low (P3HT) surface energies of substrate, it might be possible to modulate the vertical phase separation in the bulk-heterojunction. The result of vertical phase separation was determined using time-of-flight secondary-ion mass spectroscopy analysis. A controlled thickness of 50 nm for the inserted P3HT layer prevented undesirable light absorption and the power conversion efficiency of this condition was increased by 44% compared to that of a reference device.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) (Grant Nos. 2010-0029207 and 2010-0000404) founded by the government of Korea (MEST). T. I. Lee and J. M. Myoung were supported by a World Class University (WCU) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (Grant No. R32-2003). The authors also thank Dr. J. B. Kim and Professor Y. S. Kim for their fruitful discussions.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)