Patternable brush painting process for fabrication of flexible polymer solar cells

The brushing painting method is one of the typical solution processes, which makes it possible to fabricate electronic devices by simply using polymers. For the fabrication of modules and large-area devices, however, a patterning process is required for each layer. Due to the problems associated with the conventional patterning, many studies have been conducted to develop new patterning . In this study, we successfully fabricated bulk heterojunction (BHJ) structured polymer solar cells (PSCs) on a plastic substrate with an active layer through the brushing painting process. In particular, flexible PSCs with hole transporting and photo-active layers formed by the repositionable adhesive-based patterning method were fabricated to produce large-area solar cells. The fabricated PSCs exhibited Jsc, Voc, FF and power conversion efficiency (PCE) values of 8.5 mA/cm2, 0.636 V, 48.8% and 2.6%, respectively. In other words, they were more efficient than those fabricated by the spin coating method. In particular, an increase in the Jsc and FF values was observed when the series resistance (Rs) decreased to 29 Ω cm2 while the shunt resistance (Rsh) increased to 2018 Ω cm2.