Tuning the frontier molecular orbital energy levels of<i>n</i>-type conjugated copolymers by using angular-shaped naphthalene tetracarboxylic diimides, and their use in all-polymer solar cells with high open-circuit voltages
open‐circuit voltage (Voc) up to 0.94 V due to their relative high‐lying lowest unoccupied molecularorbitalenergylevels. The high Voc of 0.94 V is higher than that of solarcells based on linear‐shaped NDI‐containing polymers (<0.6 V). The results indicate that the angular‐shaped NDI is a promising building block for constructing nonfullerene polymer acceptors for solarcells with high open‐circuit