Recent Advances in Organic Photovoltaic Materials Based on Thiazole‐Containing Heterocycles

Abstract

Organic solar cells (OSCs) have achieved great progress, driven by the rapid development of wide bandgap electron donors and narrow bandgap non‐fullerene acceptors (NFAs). Among a large number of electron‐accepting (A) building blocks, thiazole (Tz) and its derived fused heterocycles have been widely used to construct photovoltaic materials, especially conjugated polymers. Benefiting from the electron deficiency, rigidity, high planarity, and enhanced intra/intermolecular interactions of Tz‐containing heterocycles, some related photovoltaic materials exhibit proper energy levels, optimized molecular aggregation, and active layer morphology, leading to excellent photovoltaic performance. This review focuses on the progress of Tz‐based photovoltaic materials in the field of OSCs. First, the Tz‐based donor and acceptor photovoltaic materials are reviewed. Then, the materials based on promising Tz‐containing heterocycles, mainly including thiazolo[5,4‐d]thiazole (TzTz), benzo[1,2‐d:4,5‐d’]bis(thiazole) (BBTz), and benzo[d]thiazole (BTz) are summarized and discussed. In addition, the new emerging Tz‐fused structures and their application in OSCs are introduced. Finally, perspectives and outlooks for the further development of Tz‐containing heterocycle‐based photovoltaic materials are proposed.

Cost-effective polymer donors with simple structure for organic solar cells

“…Thus, heterocyclic photovoltaic materials show great potential for building efficient OSCs. 144 Li et al 106 synthesized a structure-simple D–A copolymer PTQ10 in only 2 steps with difluorine-substituted Qx as the acceptor unit, and devices based on this polymer yielded a PCE of 12.7% (Fig. 13).…”

Donor–Acceptor Conjugated Polymers for Single-Component Near-Infrared II Organic Phototransistors with Ultrahigh Photoresponsivity

“…Among different NIR-II absorbers, narrow-bandgap (<1.6 eV) conjugated polymers are an emerging family of organic semiconductors, generating excitons by low-energy photons. − To achieve broad optical absorption, high mobility, and efficient photodetection, the mainstream approach is designing tailored donor–acceptor (D–A) interactions in conjugated polymers (so-called D–A conjugated polymers). − The main backbone comprises alternating electron-rich (donor, D) and electron-poor (acceptor, A) building units, in which the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are optimized by intramolecular/intermolecular interactions. − So far, a large number of D–A conjugated polymers (e.g., PIIG-oFT2, PPhTQ, PBIBDF-BT, PODTPPD-BT, and PDPP , ) have been successfully synthesized for optoelectronic applications. Notably, thiophene-based donor units show a variety of intra- and intermolecular interactions due to the high polarizability of sulfur electrons, while large polycyclic π-systems of acceptor moieties readily tune HOMO/LUMO energy levels. − However, owing to the strong intramolecular charge-transfer effect, the low energy absorption band of D–A conjugated polymers induces the separation between the HOMO and the LUMO, leading to the low oscillator strength for HOMO to LUMO electronic transitions. − Therefore, despite considerable progress having been made in the development of material synthesis, D–A conjugated polymers with NIR light absorption beyond 1200 nm have rarely been reported.…”