A Series of New Medium‐Bandgap Conjugated Polymers Based on Naphtho[1,2‐c:5,6‐c]bis(2‐octyl‐[1,2,3]triazole) for High‐Performance Polymer Solar Cells

: A series of novel conjugated copolymers based on naphtho[1,2-c:5,6-c]bis(2-octyl-[1,2,3]triazole) (TZNT) are synthesized. These copolymers exhibit medium bandgaps of ≈1.9 eV. One of them demonstrates a high performance of up to 6.10% power conversion efficiency in a bulk-heterojunction (BHJ) solar-cell device. The performance can be further enhanced to 7.11% when applied in an inverted device architecture, using PF3 N-OX as an interfacial modifier.