Interplay between Interfacial Structures and Device Performance in Organic Solar Cells: A Case Study with the Low Work Function Metal, Calcium
| Autor: | Wei Zhang, Junfa Zhu, Yaw-Wen Yang, Xiao Pan, Chia-Hsin Wang, David S. Ginger, Kristina M. Knesting, Huanxin Ju |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Materials science Organic solar cell business.industry Photoemission spectroscopy Synchrotron radiation 02 engineering and technology Polymer Electron 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Cathode 0104 chemical sciences law.invention Dipole chemistry law Optoelectronics General Materials Science Charge carrier 0210 nano-technology business |
| Zdroj: | ACS Applied Materials & Interfaces. 8:2125-2131 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.5b10641 |
| Popis: | A better understanding of how interfacial structure affects charge carrier recombination would benefit the development of highly efficient organic photovoltaic (OPV) devices. In this paper, transient photovoltage (TPV) and charge extraction (CE) measurements are used in combination with synchrotron radiation photoemission spectroscopy (SRPES) to gain insight into the correlation between interfacial properties and device performance. OPV devices based on PCDTBT/PC71BM with a Ca interlayer were studied as a reference system to investigate the interfacial effects on device performance. Devices with a Ca interlayer exhibit a lower recombination than devices with only an Al cathode at a given charge carrier density (n). In addition, the interfacial band structures indicate that the strong dipole moment produced by the Ca interlayer can facilitate the extraction of electrons and drive holes away from the cathode/polymer interface, resulting in beneficial reduction in interfacial recombination losses. These results help explain the higher efficiencies of devices made with Ca interlayers compared to that without the Ca interlayer. |
| Databáze: | OpenAIRE |
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