Properties and Indiffusion of Metals at the Interfaces with Organic Semiconductors

Morphological Properties and Indiffusion of Metals at the Interfaces with Organic Semiconductors 

The latter effect originates from the coupling between the incident and scattered radiation with localized and/or collective plasmon resonances in the rough metal film. Therefore the intensity of the totally symmetric Ag modes is very sensitive to the morphology of the metal film. 

The PES studies (see Ref. [2]) showed that the metallic character of Mg clusters occurs at coverages above 1.6 nm for PTCDA and between 9 nm and 15nm for DiMe-PTCDI. The large difference in the nominal thickness for which the metallic character of Mg clusters is formed on the two molecules is probably related to the different morphology of the underlying organic layer. 

The signal from PTCDA and DiMe-PTCDI internal modes remains visible even for a metal coverage of 43 nm, with higher intensity compared to the pure organic film. For Ag deposition onto DiMe-PTCDI no saturation of the signal intensity was observed up to a coverage of 263 nm. 

Considering that /q is the intensity of the light incident on the sample, d is the nominal thickness of the metal coverage and S is the light penetration depth in the metal, the light intensity I scattered by the sample can be described by  

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