Organic Photovoltaic Cells Based on Nonhalogenated Polymer Donors and Nonhalogenated A-DA'D-A-Type Nonfullerene Acceptors with High VOC and Low Nonradiative Voltage Loss

Jialing Zhou; Zehua He; Yanming Sun; Ailing Tang; Qiang Guo; Erjun Zhou

doi:10.1021/acsami.2c10059

Organic Photovoltaic Cells Based on Nonhalogenated Polymer Donors and Nonhalogenated A-DA'D-A-Type Nonfullerene Acceptors with High V_OC and Low Nonradiative Voltage Loss

ACS Appl Mater Interfaces. 2022 Sep 14;14(36):41296-41303. doi: 10.1021/acsami.2c10059. Epub 2022 Sep 2.

Authors

Jialing Zhou^{1

2}, Zehua He^{1

3}, Yanming Sun⁴, Ailing Tang¹, Qiang Guo³, Erjun Zhou^{1

2}

Affiliations

¹ CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Henan Institutes of Advanced Technology, Zhengzhou University, Zhengzhou 450003, China.
⁴ School of Chemistry, Beihang University, Beijing 100191, China.

PMID: 36052498
DOI: 10.1021/acsami.2c10059

Abstract

Compared with other all-inorganic/organic-inorganic hybrid solar cells, the large voltage loss (V_loss) of organic photovoltaic (OPV) cells, especially the nonradiative voltage loss (ΔV_nonrad), limited the further improvement of performance. Although A-DA'D-A-type Y-series nonfullerene acceptors (NFAs) largely improve the power conversion efficiencies (PCEs) to 18%, the open-circuit voltage (V_OC) of this kind of material was still restricted to below 1.0 V. Herein, we designed and synthesized a narrow bandgap (E_g = 1.41 eV) acceptor BTA77 with an A-DA'D-A-type backbone containing a nonhalogenated terminal group to achieve high electroluminescence efficiency and high V_OC. Combined with the nonhalogenated polymer PBDB-T with a conjugated thiophene side chain, BTA77 realized a V_OC of 0.944 V, a V_loss of 0.552 V, and a PCE of 13.75%, which is one of the highest PCEs based on nonhalogenated A-DA'D-A-type acceptors with V_OC > 0.9 V. After further blending with the nonhalogenated donor polymer PBT1-C with a conjugated phenyl side chain, the V_OC increases to 1.021 V with a super low ΔV_nonrad of 0.14 V owing to the greatly improved electroluminescence external quantum efficiency (EQE_EL) of 4.42 × 10^-3. Our results indicate that there is still a large room to decrease the ΔV_nonrad and increase V_OC by synergistic molecular engineering of p-type polymers and n-type small molecules.

Keywords: A-DA′D-A type; high voltage; nonfullerene acceptor; nonhalogenated polymer; voltage loss.