Annealing-free alcohol-processable MoOX anode interlayer enables efficient light utilization in organic photovoltaics

Abstract Molybdenum oxide (MoOX) is a commonly used hole extraction material in organic photovoltaics. The MoOX interlayer is deposited typically via thermal evaporation in vacuum. To meet the need for roll-to-roll manufacturing, solution processing of MoOX without post-annealing treatment is essential. Herein, we demonstrate an effective approach to produce annealing-free, alcohol-processable MoOX anode interlayers, namely S-MoOX, by utilizing the bis(catecholato) diboron (B2Cat2) molecule to modify the surface oxygen sites in MoOX. The formation of surface diboron-oxygen complex enables the alcohol solubility of S-MoOX. An enhanced light utilization is realized in the S-MoOX-based organic photovoltaics. This affords a superior short-circuit current density (JSC) close to 26 mA cm−2 and ultimately a high power-conversion efficiency (PCE) of 15.2% in the representative PM6:Y6 based inverted OPVs, which is one of the highest values in the inverted OPVs using an as-cast S-MoOX anode interlayer.