TY - JOUR T1 - Adsorption of oriented carborane dipoles on a silver surface JF - Physica Status Solidi B Y1 - 2016 A1 - Aliaksei Vetushka A1 - Laetitia Bernard A1 - Olga Guseva A1 - Zdenek Bastl A1 - Jiří Plocek A1 - Ivo Tomandl A1 - Antonin Fejfar A1 - Tomas Base A1 - Patrik Schmutz KW - carborane KW - Kelvin probe force microscopy KW - self-assembled monolayers KW - silver KW - time-of-flight secondary ion mass spectrometry KW - X-ray photoelectron spectroscopy AB -
Modification of surfaces with self-assembled mono-layers (SAMs) represents a powerful and innovative tool for adjusting physical and chemical properties of surfaces. The adsorption of isomeric molecules with relatively strong and oppositely oriented molecular dipoles, 1,2-(HS)2-1,2-C2B10H10 and 9,12-(HS)2-1,2-C2B10H10, on a flat silver surface is investigated in order to adjust its work function in a desired way. Time-offlight secondary ion mass spectroscopy (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) are used to prove that both isomers (i) chemisorb on a silver surface as thiolates and (ii) exhibit comparable surface densities. Densely packed surfaces of both SAMs are additionally investigated by electrochemical impedance spectroscopy, and effective surface passivation is observed. Co-deposition of both derivatives is shown to enable effective and fine adjustment of the surface work function value within a range of 1V, which is confirmed by Kelvin probe force microscopy (KPFM). Experimental data indicate faster SAM formation for the former isomer. Contribution of the interface Ag–S bonds to the work function changes is quantified.
VL - 253 IS - 3 ER -