Cardanol- and Guaiacol-Sourced Solution-Processable Green Small Molecule-Based Organic Solar Cells

Abstract

An environmentally compatible organic solar cell (OSC) has potential to build a global clean energy infrastructure for the world. However, much less attention has been focused on the structures sourced from greener origins to enhance the sustainability aspect of these devices. Herein, we report a rational design, synthesis, and characterization of donor (D)-acceptor (A)based green organic small molecules, consisting of difluoro-2,1,3benzothiadiazole (BTF 2 ) as the acceptor, with thiophene (T) and renewable resource materials, cardanol (C) and guaiacol (G) as the donor materials. The reference molecule, abbreviated as T 4 BTF 2 , is fully petro-sourced, while C 2 T 2 BTF 2 and G 2 T 2 BTF 2 are partly renewable origin molecules. Broad and strong absorption characteristics ranging from 300 to 600 nm along with high thermal stability are supportive for utility of the green origin small molecules in solar cells. Density functional theory (DFT) calculations revealed that G 2 T 2 BTF 2 is more highly planar than C 2 T 2 BTF 2 due to the difference in the positioning of the alkyl/alkoxy chain. With bulk heterojunction OSCs with PC 71 BM as the acceptor, G 2 T 2 BTF 2 exhibited a high V oc of 0.83 V among all the analyzed small molecules. When compared with the reference molecule T 4 BTF 2 , G 2 T 2 BTF 2 showed a high PCE of 5.56% with a high J sc of 10.98 mA/cm 2 and FF of 0.61, whereas the PCEs of T 4 BTF 2 and C 2 T 2 BTF 2 are 3.98% and 3.23%, respectively. Our work demonstrates a rational approach to synthesize and develop green organic semiconductors using the biofeedstock derived starting materials for realizing efficient and environment compatible OSCs.

Incorporation of a Guaiacol‐Based Small Molecule Guest Donor Enables Efficient Nonfullerene Acceptor‐Based Ternary Organic Solar Cells

“…The small molecule donor (SMD) designed as D-A-D configuration consisting of difluroro-2,1-3-benzothiadiazole as the acceptor and dialkoxyphenyl-thiophene-based terminal donor units containing a lignin sourced phenol, guaiacol as the end groups. [55] This is used as third component in the P:Y6-based ternary OSCs. The medium bandgap D-A conjugated polymer P consists of ethylhexylthiophene-2yl-1H-bisthieno[3,2-e:2'3'-g]benzothiazole donor unit and fluorinated benzothiadiazole acceptor unit.…”

Synthesis and evaluation of simple multimers based on biosourced central cores as donor materials for photovoltaic applications

“…8%. 8,9 Lastly, it would be impossible to list examples of biosourced key building blocks for organic electronics without mentioning furan. 10 Obtained from lignocellulose, this chalcogenophene has been widely associated with petroleumbased derivatives for the preparation of efficient donors in OPV 11 or p-type materials for OFETs 12 or OLEDs.…”

Covalently linked benzothiadiazole-fullerene adducts for organic optoelectronic devices: synthesis and characterization

“…Use of variation in the arrangement of the acceptor (A)–donor (D) units became popular in light-harvesting materials as they allow better intramolecular charge transfer from the acceptor to the donor units, leading to improved performance of the device. 24 Alternating arrangement of units as A–D–A was first introduced by Schulze et al 25 and found that the acceptor/donor interface assists the separation of excitons as electrons in the acceptor and holes in the donor. More recently, Chen et al 26 reported that A–D–A type acceptors exhibit outstanding performance with a PCE of 17.3% in tandem geometry.…”