A2-A1-D-A1-A2 Type Non-Fullerene Acceptors with 2-(1,1-Dicyanomethylene)rhodanine as the Terminal Groups for Poly(3-hexylthiophene)-Based Organic Solar Cells

Bo Xiao; Ailing Tang; Qianqian Zhang; Gongqiang Li; Xiaochen Wang; Erjun Zhou

doi:10.1021/acsami.8b10312

A₂-A₁-D-A₁-A₂ Type Non-Fullerene Acceptors with 2-(1,1-Dicyanomethylene)rhodanine as the Terminal Groups for Poly(3-hexylthiophene)-Based Organic Solar Cells

ACS Appl Mater Interfaces. 2018 Oct 10;10(40):34427-34434. doi: 10.1021/acsami.8b10312. Epub 2018 Sep 28.

Authors

Bo Xiao^{1

2}, Ailing Tang¹, Qianqian Zhang³, Gongqiang Li³, Xiaochen Wang¹, Erjun Zhou¹

Affiliations

¹ CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology (NCNST) , Beijing 100190 , P. R. China.
² University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
³ Key Laboratory of Flexible Electronic (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , P. R. China.

PMID: 30226749
DOI: 10.1021/acsami.8b10312

Abstract

2-(1,1-Dicyanomethylene)rhodanine (RCN) is an important electron-deficient terminal unit to build non-fullerene acceptors (NFAs) having been realized high power conversion efficiency (PCE) beyond 12% with complicated p-type polymer as electron donor. However, the photovoltaic properties of RCN-based NFAs are unsatisfied when paired with the classic p-type polymer poly(3-hexylthiophene) (P3HT). In order to make a contribution in this regard, we designed two RCN-based small molecular acceptors with A₂-A₁-D-A₁-A₂ structure, BT3 and BTA3, where benzothiadiazole (BT) and benzotriazole (BTA) are bridged A₁ segments, respectively, to modulate the optoelectronic properties. As a result, P3HT:BTA3 solar cell exhibits a promising PCE of 5.64%, with a V_OC of 0.90 V and a fill factor (FF) of 0.65, which is obviously much better than that of P3HT:BT3 (PCE = 2.55%, V_OC = 0.72 V, FF = 0.61). The higher electron mobility of P3HT:BTA3 film indicates BTA3 tends to form a continuous pathway for electron transport even at a lower weight ratio of 1:0.3 than 1:0.5 for P3HT:BT3 film. Our results indicate that introducing a weak electron-withdrawing building block BTA is an effective strategy compared with the BT counterpart to improve the performance of RCN-based NFA devices.

Keywords: 2-(1,1-dicyanomethylene)rhodanine; P3HT; benzothiadiazole; benzotriazole; non-fullerene acceptors; photovoltaic.