C 60 has been used as an electron accepting and transporting material in various organic electronic devices. In such devices, Al and Ag have been adopted as a common cathode in combination with electron injection layers (EIL), e.g., LiF. We found that the initial interface formations of C 60/LiF/Al and C 60/LiF/Ag are quite different in terms of interfacial electronic structures. We measured the interfacial electronic structures with photoemission spectroscopy and found that LiF works well as an EIL on Al but performs poorly on Ag. The origin of this difference could be attributed to the larger interface dipole on Al, highlighting the importance of the choice of cathode materials.
Bibliographical noteFunding Information:
This work was supported by the BK21 project of the ministry of Education, Science and Technology, a research project of KRF (Grant No. 2011-0004748) and in part by the Yonsei University Research Fund of 2011.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)