B. Bonello et al., Evidence for the alteration of an organic/metal interface resulting from the formation of a broad interfacial layer, J APPL PHYS, 86(9), 1999, pp. 4959-4963
The alteration of the organic/electrode interface is partially responsible
for the deterioration of the electrical efficiency of some molecular electr
onic devices. We used the picosecond ultrasonics to investigate the changes
that occur at the interface copper-phthalocyanine/M (M=Al or Au) after the
electrode deposition: the absorption of an ultrashort laser pulse sets the
heterostructure into vibration and the nature of the interface is deduced
from the photoelastic response of the samples. We show that a broad interfa
cial layer is formed, the thickness of which is estimated. We show also tha
t the slow migration of metallic particles within the organic layer leads,
after a few weeks, to a broadening of the interfacial region. (C) 1999 Amer
ican Institute of Physics. [S0021-8979(99)03921-3].