Electronic structure evolution in doping of fullerene (C{sub 60}) by molybdenum trioxide

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4895784· OSTI ID:22303496

Wang, Chenggong ^[1]; Gao, Yongli ^[1]

---

1. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)

Molybdenum oxide doping of fullerene has been investigated using ultraviolet photoemission spectroscopy (UPS), X-ray photoemission spectroscopy (XPS), and inverse photoemission spectroscopy (IPES). The lowest unoccupied molecular orbital and the highest occupied molecular orbital (HOMO) can be observed directly with IPES and UPS. It is observed that the Fermi level position in fullerene is modified by molybdenum oxide doping, and the HOMO onset is shifted to less than 0.3 eV below the Fermi level. The energy level shift is found to saturate at doping ratio of 18%. Till this stage, the shift depends on the doping concentration in a semi-logarithmic scale, with a slope substantially higher than that of the traditional semiconductor theory. The XPS results indicate that charge transfer continues beyond the energy level shift saturation till the doping ratio reaches 66% as evidenced by the Mo{sup 5+} component. At higher doping concentration, there is more Mo{sup 6+} component, which indicates the saturation of the charge transfer between MoO{sub x} and C{sub 60}.

• OSTI ID: 22303496
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 11 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRONIC STRUCTURE
EV RANGE
FERMI LEVEL
FULLERENES
MOLECULAR ORBITAL METHOD
MOLYBDENUM IONS
MOLYBDENUM OXIDES
PHOTOEMISSION
SATURATION
SEMICONDUCTOR MATERIALS
ULTRAVIOLET RADIATION
X RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY