title: Use of a high electron-affinity molybdenum dithiolene complex to p-dope hole-transport layers.
abstract: Experimental and theoretical results are presented on the electronic structure of molybdenum tris[1,2-bis(trifluoromethyl) ethane-1,2-dithiolene] (Mo(tfd)(3)), a high electron-affinity organometallic complex that constitutes a promising candidate as a p-dopant for organic molecular semiconductors. The electron affinity of the compound, determined via inverse photoemission spectroscopy, is 5.6 eV, which is 0.4 eV larger than that of the commonly used p-dopant F(4)-TCNQ. The LUMO level of Mo(tfd)(3) is calculated to be delocalized over the whole molecule, which is expected to lead to low pinning potential. Efficient p-doping of a standard hole transport material (alpha-NPD) is demonstrated via measurements of Fermi level shifts and enhanced conductivity in alpha-NPD:1% Mo(tfd)(3). Rutherford backscattering measurements show good stability of the three-dimensional Mo(tfd)(3) molecule in the host matrix with respect to diffusion.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544-5263, USA. yqi@princeton.edu
authors.forename: Yabing
authors.initials: Y
authors.lastname: Qi
authors.forename: Tissa
authors.initials: T
authors.lastname: Sajoto
authors.forename: Stephen
authors.initials: S
authors.lastname: Barlow
authors.forename: Eung-Gun
authors.initials: EG
authors.lastname: Kim
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Brédas
authors.forename: Seth R
authors.initials: SR
authors.lastname: Marder
authors.forename: Antoine
authors.initials: A
authors.lastname: Kahn