The Original Design Principles of the Y-Series Nonfullerene Acceptors, from Y1 to Y6

Since 2019, the power conversion efficiencies of organic photovoltaics have risen sharply from similar to 13% to similar to 19% because of the newly invented Y-series nonfullerene acceptors (Y-NFAs; mainly Y1 to Y6). However, comprehensive insights into the design principles behind these molecules have not been fully elucidated or explained in the literature. In this Perspective, I share our original insights into the understanding, prediction, and design principles of Y1 to Y6 and offer a brief history behind the discoveries of the Y-NFAs.

Automated summary

The power conversion efficiencies of organic photovoltaics have significantly increased since 2019, thanks to the newly invented Y-series nonfullerene acceptors (Y-NFAs). However, the comprehensive insights into the design principles behind these molecules are still not fully elucidated in the literature. The Perspective shares original insights into the understanding, prediction, and design principles of Y1 to Y6, along with a brief history behind the discoveries of the Y-NFAs.