PBDB-T-Based Binary-OSCs Achieving over 15.83% Efficiency via End-Group Functionalization and Alkyl-Chain Engineering of Quinoxaline-Containing Non-Fullerene Acceptors

Manohar Reddy Busireddy; Tsung-Wei Chen; Sheng-Ci Huang; Yi-Jia Su; Yu-Min Wang; Wei-Tsung Chuang; Jiun-Tai Chen; Chain-Shu Hsu

doi:10.1021/acsami.2c09614

PBDB-T-Based Binary-OSCs Achieving over 15.83% Efficiency via End-Group Functionalization and Alkyl-Chain Engineering of Quinoxaline-Containing Non-Fullerene Acceptors

ACS Appl Mater Interfaces. 2022 Sep 14;14(36):41264-41274. doi: 10.1021/acsami.2c09614. Epub 2022 Aug 30.

Authors

Manohar Reddy Busireddy^{1

2}, Tsung-Wei Chen^{1

2}, Sheng-Ci Huang^{1

2}, Yi-Jia Su^{1

2}, Yu-Min Wang^{1

2}, Wei-Tsung Chuang³, Jiun-Tai Chen^{1

2}, Chain-Shu Hsu^{1

2}

Affiliations

¹ Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.
² Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.
³ National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu 30010, Taiwan.

PMID: 36041037
DOI: 10.1021/acsami.2c09614

Abstract

Molecular backbone modification, alkyl-chain engineering, and end-group functionalization are promising strategies for developing efficient high-performance non-fullerene acceptors (NFAs). Herein, two new NFAs, named TPQ-eC7-4F and TPQ-eC7-4Cl, are designed and synthesized. Both molecules have linear octyl chains on fused quinoxaline-containing heterocyclics as the central backbone and difluorinated (2F)/dichlorinated (2Cl) 1,1-dicyanomethylene-3-indanone (IC) as the end-group units. The influences of alkyl-chains on fused quinoxaline backbone and different halogenated end-groups on optical, electrochemical, and photovoltaic performances of organic solar cells (OSCs) are studied. In comparison with TPQ-eC7-4Cl, TPQ-eC7-4F exhibits blue-shifted absorptions with higher molar extinction coefficients in the film state as well as in the donor/acceptor (D/A) blend film state and up-shifting lowest unoccupied molecular orbital (LUMO) energy level. As a result, the OSC devices based on the PBDB-T:TPQ-eC7-4F display an outstanding power conversion efficiency (PCE) of 15.83% with a simultaneously increased open-circuit voltage (V_oc) of 0.85 V, a short-circuit current-density (J_sc) of 25.89 mA cm^-2, and a fill factor (FF) of 72.20%, whereas the PBDB-T:TPQ-eC7-4Cl-based OSC device shows a decent PCE of 14.48% with a V_oc of 0.84 V, a J_sc of 24.56 mA/cm², and an FF of 69.77%. To the best of our knowledge, this is the highest photovoltaic performance of PBDB-T-based single-junction binary-OSCs. In comparison, ascribed to the high crystallinity and low solubility of BTP-eC7-4Cl, the corresponding PBDB-T:BTP-eC7-4Cl-based OSC device shows poor photovoltaic performance (PCE of 11.87%). The experimental results demonstrate that fine-tuning the fused quinoxaline backbone with alkyl-chain and end-group functionalization are promising strategies to construct high-performance NFAs for PBDB-T-based single-junction binary-OSCs.

Keywords: OSCs; end-group functionalization; non-fullerene acceptors; power conversion efficiency; quinoxaline; side-chain engineering.