Benzodithiophene‐Fused Perylene Bisimides as Electron Acceptors for Non‐Fullerene Organic Solar Cells with High Open‐Circuit Voltage

Abstract

Tandem-junction organic solar cells require solar cells with visible light photo-response as front cells, in which an opencircuit voltage (V oc ) above 1.0 V is highly demanded. In this work, we are able to develop electron acceptors to fabricate non-fullerene organic solar cells (NFOSCs) with a very high V oc of 1.14 V. This was realized by designing perylene bisimide (PBI)-based conjugated materials fused with benzodithiophene, in which Cl and S atom were introduced into the molecules in order to lower the frontier energy levels. The fused structures can reduce the aggregation of PBI unit and meanwhile maintain a good charge transport property. The new electron acceptors were applied into NFOSCs by using Cl and S substituted conjugated polymers as electron donor, in which an initial power conversion efficiency of 6.63 % and a high V oc of 1.14 V could be obtained. The results demonstrate that the molecular design by incorporating Cl and S atom into electron acceptors has great potential to realize high performance NFOSCs.found in the Supporting Information. The synthetic procedures were performed under argon atmosphere. Compound 3 aCompound 1 (200.0 mg, 0.21 mmol) and 2 a (399.6 mg, 0.51 mmol) were dissolved in 10 mL toluene. Then, the reaction mixture was flushed with argon for 15 min, and then 23 mg of Pd(PPh 3 ) 4 was added into the solution. The mixture was again flushed with argon for 20 min. The reaction solution was stirred at 115°C for 12 h. After removal of the solvent, the residue was purified by silica gel chromatography (dichloromethane: petroleum ether = 1 : 1) to afford 3 a as a purple product (257 mg, 60 %). 1 H NMR (400 MHz, CDCl 3 ): δ (ppm) 8.68-8.64 (m, 12H), 8.48-8.46 (d, 2H), 8.33 (s, 2H), 7.90 (s, 2H), 5.17 (br, 4H), 2.73-2.72 (d, 4H), 2.24 (br, 8H), 1.86 (br, 8H), 1.63 (br, 2H), 1.27-1.26 (m, 64H), 0.85-0.71 (m, 36H). HRMS (MALDI-TOF) m/z: [M] +

Structure and Dynamics of Perylene Bisimide Pigments for “Cool” Organic Coatings by Solid-State NMR: A Combined Experimental and DFT Study

“…13 C non quaternary suppression (NQS) 43 spectra were recorded by introducing a delay of 100 μs between the CP pulses and acquisition by collecting 11,000 transients. 1 H− 13 C MAS-J-HMQC (heteronuclear multiple- quantum coherence) experiments were carried out using the pulse scheme described in ref 44 at the MAS frequency of 19.53 kHz and using a ct of 1 ms for CP. Increments (128) were collected in the second dimension, with a dwell time of 23.04 μs and adding two FSLG cycles per increment.…”

“…Motivated by the general interest in this class of pigments and the potential of SSNMR, we carried out a combined 13 C and 1 H SSNMR and DFT study on P-black, with the purpose of understanding and characterizing its structural and dynamic properties in the solid state. The final aim of this work is dual.…”

“…In the past decade, perylene bisimide derivatives (PBIs) have aroused a considerable interest for the design of functional materials with many different applications, from the production of organic electronic devices, such as organic solar cells, organic light-emitting diodes, and field-effect transistors, , to their use as dyes in luminescent solar concentrators − and smart polymeric materials. , Besides, PBIs have extensively been used for the development of high-performance industrial pigments, thanks to their excellent tinctorial strength, insolubility, weather resistance, and chemical stability, as well as to the possibility of obtaining a wide variety of colors and optical properties by varying the substituents at the peripheral positions of the PBI core. − Recently, considerable interest has been addressed to the reflectivity and transparency properties of PBIs in the near-infrared (NIR) region of the electromagnetic spectrum, which make them promising candidates as “cool” organic pigments. − Nowadays, painting building roofs and façades with coatings based on “cool” pigments, which mimic the NIR reflective and transparent properties of certain green plants, is one of the most accessible strategies to reduce the warming induced by the sunlight exposure, − which is mainly due to the absorption of the NIR components of the solar emission spectrum. It has been demonstrated that this approach is effective in reducing the urban heat island effect − and the related high-energy demands in densely populated urban regions, as required by the EU regulation in the 2010/31/EU Directive.…”

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“…The main improvement observed for the twisted isomer C10.4b was the short-circuit current ( J SC = 10.27 mA cm –2 and J SC = 6.79 mA cm –2 for C10.4a ). Compounds C10.5a , b had planar conjugated backbones, but their pendant thiophene groups decreased the tendency to aggregate …”

“…Compounds C10.5a , b had planar conjugated backbones, but their pendant thiophene groups decreased the tendency to aggregate. 181 C10.5b contained additional thioether functions, which resulted in a higher HOMO level and a decreased band gap as determined by cyclic voltammetry. Absorption spectra of the two analogues were broadly similar.…”