Impact of Different π-Bridges on the Photovoltaic Performance of A-D-D′-D-A Small Molecule-Based Donors
Lingjun Yang,
Yu Wu,
Pachaiyappan Murugan,
Peng Liu,
Yulong Peng,
Zhiyong Qiu,
Zaifang Li,
Changlin Yu,
Shiyong Liu
Affiliations
Lingjun Yang
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Yu Wu
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Pachaiyappan Murugan
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Peng Liu
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Yulong Peng
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Zhiyong Qiu
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Zaifang Li
China-Australia Institute for Advanced Materials and Manufacturing (IAMM), Jiaxing University, Jiaxing 314001, China
Changlin Yu
Guangdong Provincial Key Laboratory of Advanced Green Lubricating Materials, Maoming 525000, China
Shiyong Liu
Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
Three small donor molecule materials (S1, S2, S3) based on dithiophene [2,3-d:2′,3′-d′]dithiophene [1,2-b:4,5-b′]dithiophene (DTBDT) utilized in this study were synthesized using the Vilsmeier–Haack reaction, traditional Stille coupling, and Knoevenagel condensation. Then, a variety of characterization methods were applied to study the differences in optical properties and photovoltaic devices among the three. By synthesizing S2 using a thiophene π-bridge based on S1, the blue shift in ultraviolet absorption can be enhanced, the band gap and energy level can be reduced, the open circuit voltage (VOC) can be increased to 0.75 V using the S2:Y6 device, and a power conversion efficiency (PCE) of 3% can be achieved. Also, after developing the device using Y6, S3 introduced the alkyl chain of thiophene π-bridge to S2, which improved the solubility of tiny donor molecules, achieved the maximum short-circuit current (JSC = 10.59 mA/cm2), filling factor (FF = 49.72%), and PCE (4.25%). Thus, a viable option for future design and synthesis of small donor molecule materials is to incorporate thiophene π-bridges into these materials, along with alkyl chains, in order to enhance the device’s morphology and charge transfer behavior.
