Influences of using a high mobility donor polymer on solar cell performance

We report a p-type polymer semiconductor, PDBFBT, which exhibits very high space charge limited current (SCLC) mobilities of up to 2.3 x 10(-2) cm(2) V-1 s(-1), which are among the highest reported so far. When the polymer is employed as a donor material in solution coated bulk heterojunction organic solar cells (OSCs), with PC61BM as the acceptor, an efficiency of 4.53% and very high fill factors (>70% in some cases) are achieved. Furthermore, in the inverted device configuration, consistent power conversion efficiencies are demonstrated throughout a wide range of active layer thicknesses (similar to 100 nm to similar to 800 nm). Our results demonstrate the benefits of using very high mobility donor polymers in solar cell applications and will be very useful for the development of new semiconductor materials, as well as the design of device structures for more feasible manufacturing of high efficiency, large area photovoltaic devices via high speed roll-to-roll printing processes. (C) 2013 Elsevier B. V. All rights reserved.