Simple brush-painting of Ti-doped In2O3 transparent conducting electrodes from nano-particle solution for organic solar cells

In this work, we have demonstrated that simple brush-painted Ti-doped In2O3(TIO) films can be used as a cost effective transparent anodes for organic solar cells (OSCs). By the direct brushing of TIO nanoparticles ink and rapid thermal annealing (RTA), we can simply obtain TIO electrodes with a low sheet resistance of 28.25 Omega/square and a high optical transmittance of 85.48% under atmospheric ambient conditions. In particular, the brush painted TIO films showed a much higher mobility (33.4 cm(2)/V s) than that of previously reported solution-process transparent oxide films (1-5 cm(2)/V s) due to the effects of the Ti dopant with higher Lewis acid strength (3.06) and the reduced contact resistance of TIO nanoparticles. The OSCs fabricated on the brush-painted TIO films exhibited cell-performance with an open circuit voltage (V-oc) of 0.61 V, shot circuit current (J(sc)) of 7.90 mA/cm(2), fill factor (FF) of 61%, and power conversion efficiency (PCE) of 2.94%. This indicates that brush-painted TIO film is a promising cost-effective transparent electrode for printing-based OSCs with its simple process and high performance. (C) 2013 Elsevier B.V. All rights reserved.