An organic dye containing electron‐rich cyclopentadithiophene for dye‐sensitized solar cells with an efficiency over 28% at 6,000 lux

Two new dyes MA1114 and GZ152 were synthesized to study the effect of conjugated pi-spacers on a D-A-pi-A structural framework for dye-sensitized solar cells (DSSCs). The thiophene and cyclopentadithiophene (CPDT) units were introduced as an extended pi-conjugation for MA1114 and GZ152 dyes, respectively. The DSSCs based on GZ152 dye achieved an efficiency of 8.61% under standard one sun irradiation and 28.31% under 6,000 lux illumination. Introducing an electron-rich CPDT as the extended pi-conjugated spacer prevails a broad absorption spectral profile, a high dye loading, and an excellent injection efficiency, which all contribute to excellent device performance.