Electronic states of Ca/PC61BM: Mechanism of low work function metal as interfacial material
| Autor: | Qian Xu, Xin-Yuan Bai, Shanwei Hu, Xiong Li, Hong-Nian Li, Yan Wang, Ying-Ying Du, Wen-Jie Li, Junfa Zhu, Guang-Hua Chen, De-Qu Lin, Huanxin Ju |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Photoemission spectroscopy Fermi level Doping General Physics and Astronomy 02 engineering and technology Electron 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences lcsh:QC1-999 0104 chemical sciences symbols.namesake Chemical physics Electric field symbols Molecular orbital Work function 0210 nano-technology Ohmic contact lcsh:Physics |
| Zdroj: | AIP Advances, Vol 8, Iss 3, Pp 035015-035015-7 (2018) |
| ISSN: | 2158-3226 |
| Popis: | We have studied the electronic states at Ca/PC61BM interface using photoemission spectroscopy. It is found that the state of unoccupied molecular orbitals of the top molecular layer (TML) becomes occupied by the electrons transferred from the Ca atoms. The work function of the heavily doped TML of PC61BM film is smaller than that of metal Ca, and thus the contact between the TML and metal Ca is Ohmic. A transition layer (TL) of several molecular layers forms beneath the TML due to the diffusion of the Ca atoms. The TL is conductive and aligns its Fermi level with the negative integer charge transfer level of the interior PC61BM. The built-in electric field in the TL facilitates the electron transport from the interior of the PC61BM film to the TML. |
| Databáze: | OpenAIRE |
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