Single-wall carbon nanotube-containing cathode interfacial materials for high performance organic solar cells

Water/alcohol soluble cathode interfacial materials (CIMs) are playing important roles in optoelectronic devices such as organic light emitting diodes, perovskite solar cells and organic solar cells (OSCs). Herein, n-doped solution-processable single-wall carbon nanotubes (SWCNTs)-containing CIMs for OSCs are developed by dispersing SWCNTs to the typical CIMs perylene diimide (PDI) derivatives PDIN and PDINO. The Raman and X-ray photoelectron spectroscopy (XPS) measurement results illustrate the n-doped behavior of SWCNTs by PDIN/PDINO in the blend CIMs. The blended and n-doped SWCNTs can tune the work function and enhance the conductivity of the PDI-derivative/SWCNT (PDI-CNT) composite CIMs, and the composite CIMs can regulate and down-shift the work function of cathode, reduce the charge recombination, improve the charge extraction rate and enhance photovoltaic performance of the OSCs. High power conversion efficiency (PCE) of 17.1% and 17.7% are obtained for the OSCs based on PM6:Y6 and ternary PM6:Y6:PC71BM respectively with the PDI-CNT composites CIMs. These results indicate that the n-doped SWCNT-containing composites, like other n-doped nanomaterials such as zero dimensional fullerenes and two dimensional graphenes, are excellent CIMs for OSCs and could find potential applications in other optoelectronic devices.

Automated summary

This study developed a new type of n-doped SWCNT-containing CIMs for organic solar cells, which can enhance the conductivity and regulate the cathode work function of the PDI-CNT composite CIMs to improve the performance of the solar cells. High power conversion efficiency was achieved with the PDI-CNT composite CIMs, indicating their potential for applications in other optoelectronic devices.