Ternary Polymer–Perylenediimide–Carbon Nanotube Photovoltaics with High Efficiency and Stability under Super-Solar Irradiation

Polymer solar cells (PSCs) have achieved power conversion efficiencies exceeding 10%, but their performance has been limited under concentrated sunlight because of poor stability and recombination processes despite their potential for low-cost concentrated solar power. Recently, ternary polymer solar cell blends have been explored as a strategy to improve PSC performance; however, this approach has been demonstrated only for polymer–fullerene solar cells with organic ternary additives and has not addressed stability issues under supersolar irradiation. Here, we present the first polymer solar cells comprising ternary blends of high efficiency polymers, nonfullerene perylenediimide acceptors, and semiconducting single-walled carbon nanotube additives. We find that the addition of carbon nanotubes reduces efficiency-degrading recombination and improves performance and photostability, most notably under concentrated sunlight exceeding 10 suns. The utilization of carbon nanomaterials as ternary additives in organic photovoltaics creates new opportunities for integrating solution-processed solar cells with energy conversion systems based on solar concentrators.