Subtle Morphology Control with Binary Additives for High-Efficiency Non-Fullerene Acceptor Organic Solar Cells

Ding, YQ (Ding, Yunqian)^{[ 4 ]} ; Zhang, X (Zhang, Xin)^{[ 1,2,3 ]} ; Feng, HR (Feng, Huanran)^{[ 1,2,3 ]} ; Ke, X (Ke, Xin)^{[ 1,2,3 ]} ; Meng, LX (Meng, Lingxian)^{[ 1,2,3 ]} ; Sun, YN (Sun, Yanna)^{[ 1,2,3 ]} ; Guo, ZQ (Guo, Ziqi)^{[ 1,2,3 ]} ; Cai, Y (Cai, Yao)^{[ 1,2,3 ]} ; Jiao, CC (Jiao, Cancan)^{[ 1,2,3 ]} ; Wan, XJ (Wan, Xiangjian)^{[ 1,2,3 ]} ; Li, CX (Li, Chenxi)^{[ 1,2,3 ]} ; Zheng, N (Zheng, Nan)^{[ 5 ]} ; Xie, ZQ (Xie, Zengqi)^{[ 5 ]} ; Chen, YS (Chen, Yongsheng)^{[ 1,2,3 ]} 

ACS APPLIED MATERIALS & INTERFACES, 2020, 12(24): 27425-27432

DOI: 10.1021/acsami.0c05331

摘要

Adding an additive is one of the effective strategies to fine-tune active layer morphology and improve performance of organic solar cells. In this work, a binary additive 1,8-diiodooctane (DIO) and 2,6-dimethoxynaphthalene (DMON) to optimize the morphology of PBDB-T:TTC8-O1-4F-based devices is reported. With the binary additive, a power conversion efficiency (PCE) of 13.22% was achieved, which is higher than those of devices using DIO (12.05%) or DMON (11.19%) individually. Comparison studies demonstrate that DIO can induce the acceptor TTC8-O1-4F to form ordered packing, while DMON can inhibit excessive aggregation of the donor and acceptor. With the synergistic effect of these two additives, the PBDB-T:TTC8-O1-4F blend film with DIO and DMON exhibits a suitable phase separation and crystallite size, leading to a high short-circuit current density (J(sc)) of 23.04 mA.cm(-2) and a fill factor of 0.703 and thus improved PCE.