Efficient and stable organic solar cells based on all-solution-processed metal oxide transport layers

Charge extraction from the active layers to the corresponding electrodes is one of the key processes of organic solar cells (OSCs). Herein, we developed a mild n-doping strategy for metal oxides via electron transfer from Lewis base anions, simultaneously boosting the electric and electronic properties of the solution-processed molybdenum oxide (MoOx) hole transport layers (HTLs) to enable efficient OSCs with stable interlayers. High-performance OSCs have been obtained with similar to 19% PCEs, representing one of the best-performing conventional OSCs consisting of all-solution-processed metal oxide transport layers. Such doped MoOx exhibited not only excellent thickness-insensitive features (up to 150 nm) but also excellent stability. Overall, this study provides an effective strategy to develop high-performance yet cost-effective organic optoelectronics. Doping of solution-processed molybdenum oxide hole transport layers enabled the efficient and stable organic solar cells.