Molecular Understanding of How the Interfacial Structure Impacts the Open-Circuit Voltage of Highly Crystalline Polymer Solar Cells
| Autor: | Masahiko Saito, Itaru Osaka, Takuto Hidani, Yasunari Tamai, Hideo Ohkita, Koshi Yamazaki, Tomohiro Fukuhara |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Photocurrent
chemistry.chemical_classification Materials science Organic solar cell Open-circuit voltage crystalline polymer Polymer Branching (polymer chemistry) charge transfer states Polymer solar cell open-circuit voltage chemistry Chemical physics interfacial electronic structure Side chain General Materials Science organic photovoltaics HOMO/LUMO |
| Zdroj: | ACS Applied Materials & Interfaces. 13:34357-34366 |
| ISSN: | 1944-8252 1944-8244 |
| Popis: | Herein, we study the origin of differences in open-circuit voltage (VOC) for polymer:fullerene solar cells employing highly crystalline conjugated polymers (PTzBT) based on the same thiophene–thiazolothiazole backbone with different side chains. By analyzing the temperature dependence of VOC and cyclic voltammogram, we find that the difference in VOC originates in the different cascaded energy structures for the highest occupied molecular orbital (HOMO) levels in the interfacial mixed phase. Furthermore, we find that this is due to the stabilization of HOMO caused by the different branching of side chains on the basis of density functional theory calculation. Finally, we discuss the molecular design strategy based on side-chain engineering for ideal interfacial cascaded energy structures leading to higher VOC and photocurrent simultaneously. |
| Databáze: | OpenAIRE |
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