Use of a high electron-affinity molybdenum dithiolene complex to p-dope hole-transport layers.
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.
Qi
Yabing
Y
Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544-5263, USA. yqi@princeton.edu
Sajoto
Tissa
T
Barlow
Stephen
S
Kim
Eung-Gun
EG
Brédas
Jean-Luc
JL
Marder
Seth R
SR
Kahn
Antoine
A