End-capped group modification on cyclopentadithiophene based non-fullerene small molecule acceptors for efficient organic solar cells; a DFT approach

Muhammad Imran Khan; Javed Iqbal; Sahar Javaid Akram; Yaser A El-Badry; Muhammad Yaseen; Rasheed Ahmad Khera

doi:10.1016/j.jmgm.2022.108162

End-capped group modification on cyclopentadithiophene based non-fullerene small molecule acceptors for efficient organic solar cells; a DFT approach

J Mol Graph Model. 2022 Jun:113:108162. doi: 10.1016/j.jmgm.2022.108162. Epub 2022 Mar 4.

Authors

Muhammad Imran Khan¹, Javed Iqbal², Sahar Javaid Akram¹, Yaser A El-Badry³, Muhammad Yaseen⁴, Rasheed Ahmad Khera⁵

Affiliations

¹ Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan.
² Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan; Punjab Bio-energy Institute, University of Agriculture, Faisalabad, 38000, Pakistan. Electronic address: javedkhattak79@gmail.com.
³ Department of Chemistry, Faculty of Science, Taif University, Khurma, P.O. Box 11099, Taif, 21944, Saudi Arabia.
⁴ Department of Physics, University of Agriculture, Faisalabad, 38000, Pakistan.
⁵ Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan. Electronic address: rasheedahmadkhera@yahoo.com.

PMID: 35278828
DOI: 10.1016/j.jmgm.2022.108162

Abstract

Four acceptor-donor-acceptor (A-D-A) type cyclopentadithiophene core-based non-fullerene small acceptor molecules were designed with the objective to improve the proficiency of photovoltaic cells. A comprehensive density functional theory (DFT) analysis was done by employing B3LYP functional with 6-31G(d,p) basis set to study optoelectronic properties of R as well as M1-M4 molecules, while the time-dependent self-consistent field (TDSCF) was utilized to analyze their excited state calculations. Several essential characteristics must be refined in order to enhance the efficiency of small molecular acceptors, i.e., the density of states (DOS), HOMO-LUMO band gap, transition density matrix (TDM), dipole moment, reorganization energy, light-harvesting efficiency, and open-circuit voltage, etc. In comparison to the R molecule, all the derived molecules show better maximum absorption (in chloroform solvent) with a range of 886-951 nm and a smaller band gap with a range of 1.65-1.55 eV M2 retains the least exciton binding energy of 0.24 eV, and amongst all the investigated molecules M3 molecule has the least interaction coefficient values so, it possesses better charge transport probability. The reorganization energy values in eV for both electron (0.00579) and hole (0.00737) are the least for M3 molecule, so this molecule exhibits better charge mobility for electron and hole. V_OC of R and M1-M4 molecule was calculated by theoretically computing the values of their complexes with PTB7-Th donor molecule.

Keywords: Cyclopentadithiophene based molecules; Density functional theory; Molecular electrostatic potential; Power conversion efficiency; Transition density matrix.

Publication types

Research Support, Non-U.S. Gov't