Fine‐Tuning Batch Factors of Polymer Acceptors Enables a Binary All‐Polymer Solar Cell with High Efficiency of 16.11%

Abstract

Random conjugated polymers, such as typical polymerized small molecular acceptors (PSMAs), concurrently suffer from the dual batch factors of molecular weights (MWs) and regioregularity, which seriously interfere with the study of the relationship between batch factors and polymer properties. Here, four isomer‐free PSMAs, PA‐5 and three members of a PA‐6 series with low (L), medium (M), and high (H) MWs, in which 5 and 6 define linkage position throughout conjugated backbone, are designed and synthesized to clearly investigate polymer batch effects. These studies reveal that PA‐6‐L and PA‐6‐M have ignorable batch differences within deviations, which deliver comparable maximum efficiencies of 14.81% and 14.99%, respectively. The PA‐6‐H based cell is processed from chlorobenzene with its high boiling point, due to the limited solubility in other common solvents, leading to large‐size phase separation during prolonged film drying process, and thereby inferior performance. In contrast, PA‐5 possesses diverse absorption characteristics, and ordered crystallization, which prompts higher short‐circuit current density and fill factor in the cell. As a result, the corresponding device realizes a photovoltaic performance of 16.11%, which is one of the best binary all‐polymer solar cells in the reported literature to date. This study provides a new insight into complicated batch effects of PSMAs on device performance while avoiding cross‐talk between them.

Rationally regulating the terminal unit and copolymerization spacer of polymerized small-molecule acceptors for all-polymer solar cells with high open-circuit voltage over 1.10 V

“…[26][27][28][29][30][31][32] Recently, beneting from the continuous efforts on the structural optimization of Yderivative-based PSMAs, the PCEs of all-PSCs have been rapidly boosted up to over 17%. [33][34][35][36][37][38][39][40] However, to date, the majority of reported PSMAs are narrow bandgap ones while PSMAs with wide bandgaps have not yet been explored, which are apparently pivotal for versatile applications in indoor photovoltaics, [41][42][43] and tandem as well as ternary solar cells. [44][45][46][47] Besides, the molecular structure engineering of PSMAs mainly focused on the manipulation of both the centered aromatic fused-ring moiety and side chain substituents of SMAs, and little attention was paid to the rational regulation of the terminal moiety of SMAs.…”

Binary Blend All‐Polymer Solar Cells with a Record Efficiency of 17.41% Enabled by Programmed Fluorination Both on Donor and Acceptor Blocks

“…[ 37 , 39 , 46 ] In addition, more and more recent studies have demonstrated that the regioregular PSMAs could obtain better solid‐state packing, synthetic repeatability, and less energy disorder, eventually leading to enhanced charge transport properties and device performances. [ 17 , 19 , 26 , 34 , 43 , 45 , 46 , 47 , 48 ] Therefore, it is essential to take comprehensive consideration of the DAD cores, end groups, π ‐spacers, and the regiochemistry effect to develop PSMAs toward higher performance.…”

Linker Unit Modulation of Polymer Acceptors Enables Highly Efficient Air‐Processed All‐Polymer Solar Cells

“…However, despite a number of linker units other than thiophene can behave in a similar manner while maintaining the original advantages, not much of the investigation has been made yet and their impacts on polymer properties remain unclear. Besides, most reported all-PSCs were sensitive to O 2 or moisture and had to be made in an inert gasfilled glovebox, [39,40] which is not compatible with the scalable manufacturing of organic solar modules. It is urgent to develop high-performance all-PSCs that can be fabricated in ambient conditions.…”