Ladder-Type Thienoacenaphthopyrazine-Based Molecules: Synthesis, Properties, and Application to Construct High-Performance Polymer for Organic Solar Cells

Fluorinated Polymer Donors for Nonfullerene Organic Solar Cells

“… The fluorinated polymers continue to face the challenge of high cost. The simple, high‐yield and atom‐economy fluorination method is still highly demanded. How to design new fluorinated polymers toward efficiency higher 20 % by further reducing energy loss and suppressing the charge recombination. Some studies revealed that polymer donors significantly affect morphology and device stability of OSCs [8f,17g,110–111,153] . Designing new fluorinated polymers with ultra‐strong intermolecular interactions could help to address the stability issue of OSCs. …”

“…From starting material 5,6-dibromoacenaphthylene-1,2-dione that has dibromo and diketone substitutions, Wu's group synthesized a new family of ladder-type monomers thienoacenaphthopyrazines (TAPs) and their polymers PTAP1 and PTAP2. [111] Due to ease modification of chemical structure, the frontier energy levels and electron withdrawing ability of TAPs could be easily tuned by bringing various electron-accepting groups together. The small size and very strong electron-withdrawing ability of fluorine atom make multi-fluorine substituted polymer PTAP1 exhibit higher hole mobility and more favorable phase separation than that for PTAP2.…”

“…Recently, multifluorinated units were also created for high‐performance polymer donors (Figure 13). From starting material 5,6‐dibromoacenaphthylene‐1,2‐dione that has dibromo and diketone substitutions, Wu's group synthesized a new family of ladder‐type monomers thienoacenaphthopyrazines ( TAPs ) and their polymers PTAP1 and PTAP2 [111] . Due to ease modification of chemical structure, the frontier energy levels and electron withdrawing ability of TAPs could be easily tuned by bringing various electron‐accepting groups together.…”

1,4-Azaborine based unfused non-fullerene acceptors for organic solar cells

“…[1][2][3][4][5][6] In the past few decades, great efforts have been devoted to exploring various photoactive materials to promote the power conversion efficiency (PCE) of OSCs. [7][8][9][10][11][12][13] In the past few years, the PCE of OSCs has soared to 19% mainly owing to the discovery of small molecule non-fullerene acceptors (NFAs). 14,15 In contrast to the fullerene acceptors, NFAs possessed strong near-infrared (NIR) absorption and easy structure-modication and readily tuned electronic energy levels.…”

Manipulating the Alkyl Chains of Naphthodithiophene Imide-Based Polymers to Concurrently Boost the Efficiency and Stability of Organic Solar Cells

“…In the blend film, the separated NFA domains are dispersed between the interconnecting polymer domains and the physical property of the polymer donor should play a key role in the morphology stability of the interpenetrating D/A domains. − However, very limited attention was paid to study the relationship between the polymer structure, crystallinity, and morphology stability, although it is crucially important. ,, Consequently, how to design polymer donors with high efficiency and excellent morphology stability remains challenging currently. The chemical structure of the monomer significantly affects the intermolecular interaction, crystallinity, and film forming properties of polymers. − The units with a large conjugated backbone benefit strong intermolecular interactions, which probably could provide additional strength against polymer chain movement. − Therefore, developing polymer donors based on multifused aromatic units should be a wise option to address the morphology stability issue of OSCs.…”