Enhanced performance of polymer solar cells by dipole-assisted hole extraction

Polymer solar cells (PSCs) with different anode buffer layers were fabricated to investigate dipole-assisted hole extraction on the performance improvement of PSCs. The power conversion efficiency (PCE) of PSCs was increased from 4.77% to 6.18% with 29.6% improvement due to the increased short circuit current density (Jsc) from 12.00 to 15.65 mA/cm2 induced by the oriented LiF dipole-assisted hole extraction. More hole could be swept-out from the active layers by oriented LiF dipole/PEDOT:PSS combined anode buffer layers. The dipole-assisted hole extraction could be further demonstrated from the J–V curves of hole-only devices with different anode buffer layers.