New 3,3′-(ethane-1,2-diylidene)bis(indolin-2-one) (EBI)-based small molecule semiconductors for organic solar cells

Abstract

A series of donor-acceptor-donor (D-A-D) structured small-molecule compounds, with 3,3'-(ethane-1,2-diylidene)bis(indolin-2-one) (EBI) as a novel electron acceptor building block coupled with various electron donor end-capping moieties (thiophene, bithiophene and benzofuran), were synthesized and characterized. When the fused-ring benzofuran is combined to EBI (EBI-BF), the molecules displayed a perfectly planar conformation and afforded the best charge tranport properties among these EBI compounds with a hole mobility of up to 0.021 cm 2 V -1 s -1 . All EBI-based small molecules were used as donor material along with a PC61BM acceptor for the fabrication of solution-processed bulk-heterojunction (BHJ) solar cells. The best performing photovoltaic devices are based on the EBI derivative using the bithiophene end-capping moiety (EBI-2T) with a maximum power conversion efficiency (PCE) of 1.92%, owing to the broad absorption spectra of EBI-2T and the appropriate morphology of the BHJ. With the aim of establishing a correlation between the molecular structure and the thin film morphology, differential scanning calorimetry, atomic force microscopy and X-ray diffraction analysis were performed on neat and blend films of each material.

Synthesis of 3,3’‐(Ethane‐1,2‐diylidene)bis(indolin‐2‐one) Promoted by Thermally‐activated Electron Transfer and Photoreduction of CO2 to CH4 and CO

“…Molecules containing the EBI unit have been previously applied in organic optoelectronics [45,52–53] . Application of organic conjugated molecules in CO 2 photoreduction is in an embryonic stage.…”

“…Molecules containing the EBI unit have been previously applied in organic optoelectronics. [45,[52][53] Application of organic conjugated molecules in CO 2 photoreduction is in an embryonic stage. Energetic alignment indicates that the redox potential of C is suitable for CO 2 reduction and water oxidation (Figure 4a).…”

Synthesis and Characterization of Fluorenone-Based Donor-Acceptor Small Molecule Organic Semiconductors for Organic Field-Effect Transistors

“…This could be ascribed to the extra thiophene The additional electron-rich thiophene group increases the HOMO level and could facilitate hole injection from gold electrode. 45 Overall, devices deposited at higher temperature (70 o C) exhibited higher charge carrier mobilities. Furthermore, devices on PS-treated substrates afforded better OFET performance (0.015-0.020 cm 2 /Vs) than bare SiO 2 substrates (0.00091-0.0014 cm 2 /Vs).…”

Recent Advances of Furan and Its Derivatives Based Semiconductor Materials for Organic Photovoltaics

“…Then Mylène et al did similar work by using 3,30‐(ethane‐1,2‐diylidene)bis(indolin‐2‐one) (EBI) as an electron acceptor building block coupled with various electron donor end‐capping moieties (thiophene, bithiophene and benzofuran ( BF8 )). [ 216 ] Introducing benzofuran terminal enhanced the molecular planarity, improved the intermolecular stacking, and thereby achieving a high charge transport.…”