Non-fused nonfullerene acceptors with asymmetric benzo[1,2-b:3,4-b', 6,5-b"]trithiophene (BTT) central donor core and different acceptor terminal units for organic solar cells

Ganesh D Sharma; A R Khokhlov; M L Keshtov; D Y Shikin; D Y Godovsky; V N Sergeev; J Liu; D P Kalinkin; V G Alekseev; Shyam Shankar S

doi:10.1002/chem.202403193

Non-fused nonfullerene acceptors with asymmetric benzo[1,2-b:3,4-b', 6,5-b"]trithiophene (BTT) central donor core and different acceptor terminal units for organic solar cells

Chemistry. 2024 Oct 7:e202403193. doi: 10.1002/chem.202403193. Online ahead of print.

Authors

Ganesh D Sharma¹, A R Khokhlov², M L Keshtov², D Y Shikin², D Y Godovsky³, V N Sergeev², J Liu⁴, D P Kalinkin⁵, V G Alekseev⁶, Shyam Shankar S⁷

Affiliations

¹ The LNM Institute of Information Technology, Physics, Jamdoli, 302031, Jaipur, INDIA.
² A N Nesmeyanov Institute of Organoelement Compounds RAS, Physical Chemistry, RUSSIAN FEDERATION.
³ A N Nesmeyanov Institute of Organoelement Compounds RAS, Physical Science, RUSSIAN FEDERATION.
⁴ Changchun Institute of Applied Chemistry Chinese Academy of Sciences, Applied Chemistry, CHINA.
⁵ A N Nesmeyanov Institute of Organoelement Compounds RAS, Chemistry, RUSSIAN FEDERATION.
⁶ Tver State University, Analytical Chemistry, RUSSIAN FEDERATION.
⁷ The LNM Institute of Information Technology, Physics, INDIA.

PMID: 39374185
DOI: 10.1002/chem.202403193

Abstract

Here in, we have designed two new unfused non-fullerene small molecules based on asymmetric benzo[1,2-b:3.4-b', 6,5-b"]trithiophene (BTT) central donor core and different terminal units, i.e. 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (NFA-4) and 1,3-diethyl-2-thioxodi hydropyrimidine-4,6(1H,5H)-dione (NFA-5) and their optical and electrochemical properties were investigated. Employing a wide band-gap copolymer D18, the binary D18: NFA-4 and D18:NFA-5 bulk heterojunction-based organic solar cells realized an overall power conversion efficiency of about 17.07% and 11.27 %, respectively. The higher value of power conversion efficiency for the NFA-4-based organic solar cells, as compared to the NFA-5 counterpart, is attributed to the enhanced values of short circuit current, open circuit voltage, and fill factor. After the incorporation of NFA-5 into the binary bulk heterojunction D18:NFA-4, the ternary organic solar cells attained a power conversion efficiency of 18.05 %, which is higher than that for the binary counterparts and attributed to the increased values of short circuit current, fill factor, and open circuit voltage. The increased value of short circuit current is associated with the effective utilization of excitons through the energy transfer from the NFA-5 to NFA-4 as the NFA-4 exhibits a more significant dipole moment than the NFA-5 and is effectively dissociated into a free charge carrier.

Keywords: Organic solar cells; Power conversion efficiency; Unfused non fullerene acceptors; energy transfer.