Ti₃C₂T_<i>x</i>/PEDOT:PSS Composite Interface Enables over 17% Efficiency Non-fullerene Organic Solar Cells

Metal carbide Ti₃C₂T_<i>x</i> as a new two-dimensional material with excellent metallic conductivity, good water solubility, and superior transmittance in the visible light range shows great potential for applications in optoelectronic devices. Herein, Ti₃C₂T_<i>x</i>/PEDOT:PSS composite films were fabricated by a simple solution process and employed as an anode interfacial layer in organic solar cells. By introducing the Ti₃C₂T_<i>x</i>/PEDOT:PSS composite interface into the devices, the highest power conversion efficiency (PCE) of 17.26% was achieved while using PM6:Y6 as the active layer, with a high short-circuit current (<i>J</i>_sc) of 26.52 mA/cm² and a fill factor of up to 0.76. The PCE is much higher than 15.89% for the pure PEDOT:PSS interfacial layer-based device without doping. The dramatically improved performance was attributed to the increased conductivity of the Ti₃C₂T_<i>x</i>/PEDOT:PSS composite interface and the increased charge extraction and collection efficiency of the devices. This work presents an effective method to prepare the Ti₃C₂T_<i>x</i>/PEDOT:PSS composite interface and high-performance organic solar cells.