A high dielectric constant non-fullerene acceptor for efficient bulk-heterojunction organic solar cells

A non-fullerene acceptor with a high relative dielectric constant (ε_r) over 9 is developed. It offers an efficiency of 8.5%, which is the best result for organic solar cells employing high ε_r materials. Further research should focus on morphology optimization to make high ε_r practically useful in devices.