Chlorinated Fused Nonacyclic Non-Fullerene Acceptor Enables Efficient Large-Area Polymer Solar Cells with High Scalability
Gongchu Liu, Tao Jia, Kai Zhang, Jianchao Jia, Qingwu Yin, Wenkai Zhong, Xiao’e Jia, Nan Zheng, Lei Ying, Fei Huang, Yong Cao
Abstract
As the power conversion efficiency (PCE) of polymer solar cells (PSCs) keeps increasing, developing high-performance large-area PSCs toward commercial application becomes a hot topic in this field. Here, we design and synthesize a non-fullerene acceptor TfIF-4Cl with a fused nonacyclic core via end-group chlorination. Compared to the fluorinated counterpart (TfIF-4F), the combination of the Cl atom in TfIF-4Cl not only leads to red-shifted absorption, but also improves the molecular packing ability. When TfIF-4Cl is blended with the polymer donor PM7 to fabricate the PSC, the device maintains high VOC (0.97 V, corresponding to a low energy loss of 0.60 eV) and presents enhanced JSC and high fill factor (78%), thus leading to an improved efficiency of 14% when compared with a PM7:TfIF-4F-based device. The high VOC but moderate photocurrent of PM7:TfIF-4Cl-based small-area device are beneficial to achieve large-area devices with high scalability according to the Joule’s law; thus, we manufacture 1.01 cm2 devices and achieve a remarkable PCE of 13.3%, which retain 95% in efficiency when the device area is scaled up from 0.04 to 1.01 cm2, and represent the best scalability when the device area is scaled up to 1 cm2 in the literature.