Black Phosphorous Quantum Dots Sandwiched Organic Solar Cells.

Black phosphorous quantum dots (BPQDs) possess ambipolar charge transport, high mobility, and a tunable direct bandgap. Here, liquid-exfoliated BPQDs are used as interlayers to modify both the electron transport layer and hole transport layer in organic solar cells (OSCs). The incorporation of BPQDs is beneficial to the formation of a cascade band structure and electron/hole transfer and extraction. The power conversion efficiency of the BPQDs-incorporated OSC based on PTB7-Th:FOIC blend is enhanced from 11.8% to 13.1%. In addition, power conversion efficiency enhancement is also achieved for other nonfullerene and fullerene-based devices, demonstrating the universality of this interlayer methodology.