High-Performance Inverted Organic Solar Cells with MXene-Based Interfacial Engineering

Inverted organic solar cells (OSCs) offer superior operational stability for practical applications, yet their power conversion efficiencies (PCE) lag behind those of conventional devices. This shortfall is primarily due to an excessive downshift in the electron affinity of nonfullerene acceptors, which hinders efficient charge extraction. Here, we introduce an MXene interlayer (Ti₃C₂OH_<i>x</i>) to simultaneously optimize the energetic landscape at the ZnO/active layer interface and passivate ZnO surface defects. The modified ZnO helps reduce energy barriers, mitigate nonradiative recombination, and enhance charge extraction of OSC devices, enabling a remarkable PCE of 18.55% with improved storage stability and photostability, among the highest reported for inverted OSCs. These findings establish MXene as a versatile material for interfacial engineering in high-efficiency inverted OSCs.