Recent Research Progress in Random Copolymerization of Polymer Photovoltaic Materials for High‐Performance Polymer Solar Cells

Abstract

Along with the development of narrow‐bandgap A–D–A and A–DA’D–A‐type small‐molecule acceptors (SMAs), polymer solar cells (PSCs) have witnessed a striking progress, with an impressing power conversion efficiency (PCE) approaching 20% recently. Aiming to realize the future commercial application of organic photovoltaic (OPV) technology, developing more efficient organic conjugated materials is urgently needed. Benefiting from the specific advantages in precisely adjusting the optoelectronic materials, random copolymerization strategy has drawn great attention during the past several years and has played a vital role in the development of PSCs. Herein, the functions of random copolymerization strategy in modulating the polymer properties are briefly discussed. Then the recent research progress of random copolymerization strategy of polymer photovoltaic materials in PSCs is reviewed. Finally, perspectives and a concise outlook on the further advancement of the random copolymerization strategy are put forward.

Impact of Alkyl-Based Side Chains in Conjugated Materials for Bulk Heterojunction Organic Photovoltaic Cells—A Review

“…Numerous hundreds of publications have reported the synthesis, photophysical properties, and use of conjugated polymers in OPVs. Several reviews have gathered these papers [54][55][56], emphasizing the polymerization strategy [57], the role of specific building blocks [58][59][60][61], the improvement of the active layer or cell technology [9,62,63], the achievement of transparent BHJ photoactive layers and devices [54,64], or their morphological design strategies for improving charge carrier mobilities [65]. Recently, conjugated polymer-based bulk heterojunction solar cells have exhibited high power conversion efficiencies (PCEs) up to 18.22% in 2020 [66] and up to 19.3% in a single-junction cell in 2022 [67].…”

“…Since its first report in 2008 [81], the BDT unit has often been used as a donor unit for polymer elaboration; in particular, it gave rise to its derivative, DTBDT, well known as a donor moiety in A-D-A materials. Similar donor building blocks are widely used because their symmetrical chemical structures and rigid fused aromatic systems benefit the electron delocalization and π-π stacking [57] and contributed until very recently to the achievement of outstanding OPV device performances [82]. The DTBDT moiety is built from the commercially available benzo [1,2-b:4,5-b ]dithiophene-4,8-dione and offers the possibility of introducing a large variety of side chains on the pendant thiophene units.…”