Adsorption and thermal stability of organic films on surfaces monitored by Direct Recoil Spectroscopy.

L. SALAZAR ALARCÓN, L.N. SERKOVIC LOLI, L.J. CRISTINA, J.E. GAYONE, E.A. SÁNCHEZ, O. GRIZZI.; L. CHEN, S. SHEN, V.A. ESAULOV

Paris

Conferencia; High Resolution Depth Profiling 6; 2011

The adsorption and self-assembly of organic molecules on a variety of substrates such as noble metals, transition metals with incomplete d-shells and semiconductors, is a subject of great activity in surface science and applied chemistry due to the possibility of using them as building blocks with specific electronic properties, or linkers between metallic contacts to produced optoelectronic devices. Π- conjugated or aromatic organic molecules are highly attractive building blocks as their electronic properties, the molecular arrangement and the functionality of these structures can be custom tailored through the rich chemistry of organic systems. In this work we report results on the study of the adsorption process and of the thermal stability of a EP-PTCDI (N,N?-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxdiimide ? C34H10O4N2) and BDMT (1, 4-benzene dimethanetiol ? SH-CH2-C6H4-CH2-SH) ultrathin films grown on Au and Ag, by means of Direct Recoil Spectroscopy with time-of-flight mass analysis (TOF-DRS). This technique is particularly suitable to study organic molecules [1] because a) it detects hydrogen, an element that is present on organic molecules but that is not detected by the standard surface analysis techniques, b) it is sensitive to the topmost layer of the surface, c) both neutral and ion scattered and recoiling particles are detected with similar sensitivity thus avoiding uncertainties due to the electron exchange processes, and d) the TOF analysis combined with a multichannel technique allows the use of low density currents (108 ?109 ions.s -1 .cm-2 ) producing undetectable damage within a typical analysis time.