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Cai Z, Hu R, Xiao Z, Feng J, Zou X, Wen G, Dong G, Zhang W. Charge photogeneration dynamics in non-fullerene polymer solar cells with fluorinated and non-fluorinated acceptors. J Chem Phys 2024; 160:074702. [PMID: 38364001 DOI: 10.1063/5.0177876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 01/22/2024] [Indexed: 02/18/2024] Open
Abstract
In this work, charge photogeneration and recombination processes of PM6:IDIC-4F and PM6:IDIC blend films were investigated by the steady-state and time-resolved spectroscopies, as well as the time-dependent density functional theory calculations. The peaks in absorption and photoluminescence (PL) spectra of IDIC and IDIC-4F solutions were assigned by combining the experiment and the simulation of UV-vis absorption and PL spectra. For neat acceptor films, the exciton diffusion length of neat IDIC and IDIC-4F films was estimated as ∼28.9 and ∼19.9 nm, respectively. For PM6-based blend films, we find that the fluorine substitution engineering on the IDIC acceptor material can increase the phase separate size of acceptor material in blend films, resulting in the reduction of dissociation efficiencies of acceptor excitons. In addition, we find that the charge recombination in PM6:IDIC-4F is dominated by bimolecular recombination, in comparison to geminate type carrier recombination in PM6:IDIC blend films. In addition, we find that thermal annealing treatment has a weak influence on carrier recombination but slightly reduces the exciton dissociation efficiency of acceptor in PM6:IDIC blend films, leading to a slightly reduced power conversion efficiency of PM6:IDIC solar cells. These results may shed light on the design of high-performance semiconductor molecules for application in solar cells.
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Affiliation(s)
- Zekai Cai
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China
| | - Rong Hu
- School of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
| | - Zijie Xiao
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China
| | - Junyi Feng
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China
| | - Xianshao Zou
- Qingdao Innovation and Development Base, Harbin Engineering University, Qingdao CN-266 000, China
- Division of Chemical Physics, Lund University, 221 00 Lund, Sweden
| | - Guanzhao Wen
- Research Center for Advanced Information Materials (CAIM), Huangpu Research and Graduate School of Guangzhou University, Guangzhou 510006, China
| | - Geng Dong
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China
| | - Wei Zhang
- School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China
- Research Center for Advanced Information Materials (CAIM), Huangpu Research and Graduate School of Guangzhou University, Guangzhou 510006, China
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Liu C, Wu Z, Qiu N, Li C, Lu Y. Selenophene-Containing Small-Molecule Donor with a Medium Band Gap Enables High-Efficiency Ternary Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2023; 15:9764-9772. [PMID: 36752273 DOI: 10.1021/acsami.2c21776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
To construct efficient donor:donor:acceptor (D1:D2:A)-type ternary devices, two new selenophene-containing small-molecule (SM) donors named FSBTSeEHR and FSBTSeHR have been designed and synthesized that show broader and red-shifted absorption spectra than the thiophene analogues. With the introduction of SM donors into the D18:CH-6F host system, enhanced light harvesting and charge transport were achieved, benefiting from more complementary absorptions and cascaded energy levels. Furthermore, the doping of the SM donor could effectively modulate the micromorphology and enable a more suitable phase separation size in the active layer. After systematic optimization, the FSBTSeEHR-based ternary organic solar cell (TOSC) exhibited an excellent power conversion efficiency (PCE) of 18.02% with a high open-circuit voltage (Voc) of 0.905 V, short-circuit current density (Jsc) of 26.41 mA cm-2, and fill factor (FF) of 0.754. By contrast, the FSBTSeHR counterpart showed a superior efficiency of 18.55% due to the higher Jsc (26.91 mA cm-2) and FF (0.761). The outstanding PCEs of D1:D2:A-type TOSCs based on our SM donors, FSBTSeEHR and FSBTSeHR, are significantly higher than those of the corresponding binary host system (16.86%) and among the highest values reported to date. This work demonstrates that D1:D2:A-type TOSCs have tremendous potential to achieve superior performances through elaborate design of the SM donor guest and reasonable combination of D and A ingredients.
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Affiliation(s)
- Chunyan Liu
- School of Materials Science & Engineering, Tianjin Key Laboratory for Photoelectric Materials and Devices, Key Laboratory of Display Materials & Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384, China
| | - Zhihui Wu
- School of Materials Science & Engineering, Tianjin Key Laboratory for Photoelectric Materials and Devices, Key Laboratory of Display Materials & Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384, China
| | - Nailiang Qiu
- School of Chemistry, Chemical Engineering and Materials, Jining University, Qufu 273155, China
| | - Chenxi Li
- The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials, Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yan Lu
- School of Materials Science & Engineering, Tianjin Key Laboratory for Photoelectric Materials and Devices, Key Laboratory of Display Materials & Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384, China
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