The interfacial electronic structures of a bilayer of fullerene (C60) and zinc phthalocyanine (ZnPc) grown on vanadium pentoxide (V2O5) thin films deposited using radio frequency sputtering under various conditions were studied using X-ray and ultraviolet photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO) level of the C60 layer was determined and compared with that grown on an indium tin oxide (ITO) substrate. The energy difference of a heterojunction on all V2O5 was found to be 1.3~1.4 eV, while that on ITO was 1.1 eV. This difference could be due to the higher binding energy of the HOMO of ZnPc on V2O5 than that on ITO regardless of work functions of the substrates. We also determined the complete energy level diagrams of C60/ZnPc on V2O5 and ITO.
Bibliographical noteFunding Information:
Acknowledgments: This research was supported by the Basic Science Research Programs through the National Research Foundation of Korea (Grant No. NRF-2017R1D1A3B03034867) and Yonsei University Wonju Campus Future-leading Research Initiative (Grant No. 2017-52-0071) Author Contributions: C.J.L. and S.W.C. designed the experiment. C.J.L., M.G.P., M.S.K., and J.H.H. performed the experiments and analyzed the data. C.J.L. and S.W.C. wrote the main manuscript text. S.C. Y.Y., M.-H.C., and H.L. participated in discussion through the work.
© 2018 by the authors.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Chemistry (miscellaneous)
- Molecular Medicine
- Pharmaceutical Science
- Drug Discovery
- Physical and Theoretical Chemistry
- Organic Chemistry