Enhanced efficiency of bilayer polymer solar cells by the solvent treatment method

• We have successfully demonstrated printable bilayer solar cell using an orthogonal solvent.
• We utilized the solvent treatment method to improve the performance of bilayer solar cells.
• The solvent treatment in the bilayer structure leads to significant enhancement in efficiency.

We successfully facilitated an enhancement in the efficiency of polymer bilayer solar cells using the solvent treatment method. Specifically, after creating a poly(3-hexylthiophene-2,5-diyl(P3HT)/[6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) bilayer structure by the use of an orthogonal solvent, we applied the solvent treatment method to the bilayer solar cell to improve the device performance. When the interfaces between the P3HT layer and the PCBM layer and between the PCBM layer and the Al electrode were treated with methanol, the bilayer SCs showed significantly enhanced device performance with improved Jsc FF, and PCE.