Controllable Anion Doping of Electron Acceptors for High-Efficiency Organic Solar Cells

Charge transport of organic semiconductors remains as one of the performance bottlenecks for organic optoelectronics, especially for organic solar cells (OSCs). Herein, we demonstrate that Lewis base anion doping allows effectively modulating the charge transport capabilities of a variety of electron acceptors and the corresponding optoelectronic devices. It has enabled power conversion efficiencies of 18.16% for OSCs bearing chemical dopants in active layers. We have proven that the controllable n-doping of non-fullerene acceptors is accomplished via the solid-state anion-induced electron transfer, which originally remains dormant in the solution of Lewis base anion and organic semiconductor. Hence, Lewis base anion doping presents advantages for the solution-processing of dopant/organic semiconductor mixtures. Overall, this work provides an effective, yet feasible approach for doping solution-processed semiconductors for high-performance optoelectronics.