From molecular design to high performance: interpreting the combined effect of π-linkers and acceptor groups in benzotriazole-based non-fullerene acceptors.
5 affiliations
- 1Department of Chemistry, Division of Science and Technology, University of Education Lahore 54770 Pakistan.
- 2School of Materials Science and Engineering, Hefei University of Technology Hefei 230009 China.
- 3Department of Physics, University of Sargodha 40100 Sargodha Pakistan.
- 4International Graduate School of Nanoscience and Technology, College of Interdisciplinary and Integrative Studies, Chulalongkorn University Bangkok 10330 Thailand.
- 5Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University P.O. Box 16100 FI-00076 Aalto Finland [email protected].
Abstract
The combined effect of π-linkers and terminal groups presents a powerful yet underexplored strategy for boosting the performance of benzotriazole (BZ)-based non-fullerene acceptors (NFAs). In this computational study, we employ density functional theory (DFT) and time-dependent DFT (TD-DFT) to design and evaluate the photovoltaic performance of five benzotriazole (BZ)-core-based non-fullerene small molecule acceptors (BD1-BD5). These molecules are engineered by modifying the terminal acceptor groups of a reference structure (BZE-31) and incorporating a methyl thieno[3,4-b]thiophene-2-carboxylate π-linker. The designed molecules exhibit a pronounced bathochromic shift in absorption (λ max = 690-939 nm in chloroform) and significantly reduced optical band gaps (1.66-2.24 eV) compared to the reference. In particular, BD4, functionalized with a 4-methylene-5-oxocyclopent-1-ene-1-sulfonyl chloride end-group, demonstrates the most promising optoelectronic profile. It achieves the narrowest band gap (1.66 eV), the highest red-shifted absorption (939 nm), the lowest exciton binding energy (0.31 eV), and an exceptional short-circuit current density (J sc ≈ 22 mA cm⁻²). This superior optoelectronic synergy transforms into an idealized theoretically estimated power conversion efficiency (PCE) of 23.48% for BD4. Concurrently, BD1 (with a malononitrile end-group) also shows superior performance, with a high predicted PCE. A comprehensive analysis of frontier molecular orbitals, density of states, transition density matrices, and global reactivity descriptors confirms effective intramolecular charge transfer and favorable charge separation in the designed systems. The estimated PCEs for the most promising candidates, BD4 and BD1, reach 23.48% and 22.61%, respectively. This work provides a detailed theoretical blueprint demonstrating that π-linker incorporation and strategic terminal group engineering work in a combined manner and are highly effective strategies for tailoring the optoelectronic properties of BZ-based NF-SMAs. The high-performance candidates (BD1 and BD4) offer valuable theoretical insights for the experimental synthesis of next-generation, high-efficiency organic photovoltaic materials.
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BibTeX
@article{ateeq2026from,
title = {{From molecular design to high performance: interpreting the combined effect of π-linkers and acceptor groups in benzotriazole-based non-fullerene acceptors.}},
author = {Komal Ateeq and Muhammad Kamran Shehzad and Yasir Altaf and Maaz Ur Rehman and Rabia Bassran and Muhammad Farhan Waris and Fahim Ahmed and Farasat Haider and Basit Ali},
journal = {RSC advances},
year = {2026},
month = oct,
doi = {10.1039/d6ra05880a},
url = {https://europepmc.org/article/MED/42898668},
note = {CC BY},
}
RIS
TY - JOUR
TI - From molecular design to high performance: interpreting the combined effect of π-linkers and acceptor groups in benzotriazole-based non-fullerene acceptors.
AU - Komal Ateeq
AU - Muhammad Kamran Shehzad
AU - Yasir Altaf
AU - Maaz Ur Rehman
AU - Rabia Bassran
AU - Muhammad Farhan Waris
AU - Fahim Ahmed
AU - Farasat Haider
AU - Basit Ali
PY - 2026
DA - 2026/10/19
JO - RSC advances
DO - 10.1039/d6ra05880a
UR - https://europepmc.org/article/MED/42898668
AB - The combined effect of π-linkers and terminal groups presents a powerful yet underexplored strategy for boosting the performance of benzotriazole (BZ)-based non-fullerene acceptors (NFAs). In this computational study, we employ density functional theory (DFT) and time-dependent DFT (TD-DFT) to design and evaluate the photovoltaic performance of five benzotriazole (BZ)-core-based non-fullerene small molecule acceptors (BD1-BD5). These molecules are engineered by modifying the terminal acceptor groups of a reference structure (BZE-31) and incorporating a methyl thieno[3,4-b]thiophene-2-carboxylate π-linker. The designed molecules exhibit a pronounced bathochromic shift in absorption (λ max = 690-939 nm in chloroform) and significantly reduced optical band gaps (1.66-2.24 eV) compared to the reference. In particular, BD4, functionalized with a 4-methylene-5-oxocyclopent-1-ene-1-sulfonyl chloride end-group, demonstrates the most promising optoelectronic profile. It achieves the narrowest band gap (1.66 eV), the highest red-shifted absorption (939 nm), the lowest exciton binding energy (0.31 eV), and an exceptional short-circuit current density (J sc ≈ 22 mA cm⁻²). This superior optoelectronic synergy transforms into an idealized theoretically estimated power conversion efficiency (PCE) of 23.48% for BD4. Concurrently, BD1 (with a malononitrile end-group) also shows superior performance, with a high predicted PCE. A comprehensive analysis of frontier molecular orbitals, density of states, transition density matrices, and global reactivity descriptors confirms effective intramolecular charge transfer and favorable charge separation in the designed systems. The estimated PCEs for the most promising candidates, BD4 and BD1, reach 23.48% and 22.61%, respectively. This work provides a detailed theoretical blueprint demonstrating that π-linker incorporation and strategic terminal group engineering work in a combined manner and are highly effective strategies for tailoring the optoelectronic properties of BZ-based NF-SMAs. The high-performance candidates (BD1 and BD4) offer valuable theoretical insights for the experimental synthesis of next-generation, high-efficiency organic photovoltaic materials.
SN - 2046-2069
ER -