Chlorinated Wide-Bandgap Donor Polymer Enabling Annealing Free Nonfullerene Solar Cells with the Efficiency of 11.5%

• DOI: 10.1021/acs.jpclett.8b03247
• Publication Date: 2018-11-28T18:14:39Z
• Authors: Zhitian Liu; Yerun Gao; Jun Dong; Minlang Yang; Ming Liu; Yu Zhang; Jing Wen; Haibo Ma; Xiang Gao; Wei Chen; Ming Shao
• Keywords: Acceptor; Miscibility; Charge carrier

Substituting the hydrogen atoms on conjugated side chain of a wide-bandgap polymer J52 with chlorine can simultaneously increase Jsc, Voc, and FF nonfullerene OSCs, leading to an efficiency boost from 3.78 11.53%, which is among highest efficiencies for as-cast OSCs reported date. To illustrate impressive 3-fold PCE enhancement, chlorination effect optical properties energy levels polymers, film morphology, underlying charge dynamics systematically investigated. Grazing incidence wide-angle X-ray scattering studies show that chlorinated J52-2Cl exhibits strong molecule aggregation, preferred face-on orientation, enhanced intermolecular π–π interactions, hence increasing carrier mobility by 1 order magnitude. Moreover, modifies miscibility between donor acceptor consequently optimizes phase separation morphology J52-2Cl:ITIC blend films. These results highlight as promising approach achieve highly efficient without any extra treatment.