Scanning Kelvin probe study of photolabile silane surface modification of indium tin oxide

The scanning Kelvin nanoprobe (SKN) is an exquisitely sensitive device capable of detecting subtle changes in work function associated with alteration of surface chemistry and interfacial dipole. This instrument is highly versatile and has notably been recently used for (i) the investigation of biological interactions occurring at the interface of multiplexed microarrayed platforms and (ii) the characterization of high work function materials for application in molecular optoelectronics. Herein, we further implement the SKN to characterize, along with angle-resolved X-ray photoelectron spectroscopy and contact angle goniometry, the surface modification of indium tin oxide substrates with photopatternable silane adlayers. These molecular films are constructed in a straightforward and economical manner from alkyltrichlorosilane surface-modifying molecules that possess a distal, UV-photolabile o-nitrobenzyl moiety. Employing a photomask, we were able to selectively pattern regions of the photoreactive silane adlayer and confirm the corresponding changes in surface potential through contact potential difference measurements. Copyright (C) 2013 John Wiley & Sons, Ltd.