Hybrid Quantum Dot/Organic Heterojunction: A Route to Improve Open-Circuit Voltage in PbS Colloidal Quantum Dot Solar Cells
Yannan Zhang, Yuanyuan Kan, Ke Gao, Mengfan Gu, Yao Shi, Xuliang Zhang, Ye Xue, Xuning Zhang, Zeke Liu, Yuan Zhang, Jianyu Yuan, Wanli Ma, Alex K.‐Y. Jen
Abstract
We have successfully demonstrated the effect of a thin organic bulk-heterojunction (BHJ) interlayer on improving the photovoltaic performance of lead sulfide (PbS) colloidal quantum dot (CQD) solar cells. Multiple organic BHJ films with PTB7-Th blending with various N-type acceptors have been introduced as hole-transporting layer (HTL) in PbS solar cells. Significant enhancement in Voc was achieved in the hybrid devices compared to devices based on conventional HTLs like 1,2-ethanedithiol-treated PbS. Systematic characterizations reveal that the hybrid CQD/organic BHJ architecture can effectively modulate the interfacial charge dynamics and lead to enhanced external quantum efficiency, resulting in a champion efficiency of 12.02%. Solution-processed hybrid CQD/organic architecture may become a universal approach to improve the photovoltaic performance and scalability of PbS CQD solar cells.