An amorphous N-type polymer based on perylenediimide and selenophene for all-polymer solar cells application

• An n-type amorphous conjugated polymer, PSe-PDI, was synthesized.
• The miscibility could be improved by introducing TTV side chain to p-type polymer.
• DIO could increase the electron mobility of amorphous PDI-based polymer.
• The PCE of TTV7: PSe-PDI blend solar cell reached 2.55% with DIO as solvent additive.

An amorphous n-type polymer (PSe-PDI) consisting of perylenediimide and selenophene units was synthesized and applied in bulk heterojunction organic solar cells as an electron acceptor. The all-polymer solar cells based on PTB7 as a donor exhibited power conversion efficiency (PCE) of 1.14%. By using a PTB7 analog with conjugated tris(thienylenevinylene) side chains (TTV7) a superior photovoltaic performance with PCE of 1.81% was achieved due to the improvement of miscibility of the two polymers. Furthermore, by using diiodooctane (DIO) as additive to increase and balance the charge carrier mobility in the TTV7:PSe-PDI blend films, the PCE was increased to 2.55% with a much higher short-circuit current density of 8.34 mA/cm2. This study provides a simple and effective approach to improve the miscibility and charge carrier mobility of amorphous PDI-based all-polymer solar cells.

Figure optionsDownload as PowerPoint slide