Self-Assembled Monomolecular Layer Modified ZnO for Efficient Inverted Polymer Solar Cells with 11.53% Efficiency

Interfacial materials play a vital role in determining the charge carrier collection for the performance of polymer solar cells (PSCs). Herein, a monomolecular (3-aminopropyl) triethoxysilane (APTES) layer is deposited onto ZnO, acting as cathode interfacial layer (CIL) in the inverted PSCs. Inverted PBDB-T:IT-M PSCs with the ZnO-APTES CILs exhibit a power conversion efficiency of 11.53% with a short-circuit current density of 18.37 mA cm⁻², an open-circuit voltage of 0.91 V and fill factor of 68.77%. More than 13% improvement on the power conversion efficiency is achieved by inserting APTES, due to efficient charge collection obtained by a built-in electric field and reduced oxygen defects at the ZnO surface. The results indicate that the ZnO-APTES layer is an efficient CIL for inverted PSCs.