All-fused-ring small molecule acceptors with near-infrared absorption

Abstract

The development of small molecule electron acceptors with near infrared (NIR) absorption has led to great progress in organic solar cells (OSCs). However, the stability is a barrier limiting the...

Novel Materials for Semi-Transparent Organic Solar Cells

“…Over the last few years, a variety of materials have been commonly used as the D units in copolymers for OSC devices. These include benzo [1,2-b:4,5-b ′ ]dithiophene (BDT) [44], carbazole [45], thiophene [46,47], and benzo [1,2-b:4,5-b ′ ]difuran [48,49]. As for the A units, the most frequently employed materials are benzothiadiazole [50][51][52], benzotriazole [53], and benzodithiophene-4,8-dione (BDD) [54].…”

Superior End-Group Stacking Promotes Simultaneous Multiple Charge-Transfer Mechanisms in Organic Solar Cells with an All-Fused-Ring Nonfullerene Acceptor

“…Due to the excellent photostability and chemical stability, OSCs composed of D18:FM1 exhibit only a 9% decrease in the PCE after 16 h of simulated solar irradiation, which is much less than that of the state-of-the-art OSC device of D18:Y6 (46%) . By extending the conjugation of the core and introducing fluorine atoms at the end groups, the band gaps of the dodecacyclic FM3 and FM4 were reduced to 1.44 and 1.33 eV, respectively, resulting in a red shift of the absorption to the NIR region with a PCE of 11.36% using the D18 donor . Later, they also designed FM2 composed of 14 aromatic rings, which have a narrower band gap and strong near-infrared absorption over 1000 nm, and the fixed and rigid molecular chain that reduces the trap density making it an excellent organic photodetector material .…”

“…27 By extending the conjugation of the core and introducing fluorine atoms at the end groups, the band gaps of the dodecacyclic FM3 and FM4 were reduced to 1.44 and 1.33 eV, respectively, resulting in a red shift of the absorption to the NIR region with a PCE of 11.36% using the D18 donor. 28 Later, they also designed FM2 composed of 14 aromatic rings, which have a narrower band gap and strong near-infrared absorption over 1000 nm, and the fixed and rigid molecular chain that reduces the trap density making it an excellent organic photodetector material. 29 However, the AFRA has been demonstrated to be highly stable and promising, yet they are relatively delayed in development in terms of their reported types and PCE for constructing OSCs compared to those of typical NFAs.…”

Optimizing stability through conformational locking and ring fusion modulation in organic semiconductors

“…These unique structures exhibit distinct electronic and optical properties, making them of particular interest in the design of materials for optoelectronic applications. [1][2][3][4][5][6][7][8] Incorporation of heteroatoms into a conjugated ladder framework leads to the formation of heteroacenes. These moieties are synthesized through various ringclosure strategies, 7 including stepwise ladderization, 9 heteroannulation, 5,10,11 reductive cyclization, [11][12][13][14] oxidative cyclization, 15 acid catalysed condensation, 8 B,Nembedding, 16,17 and imide bridge installation.…”