Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

Aymeric Vecchiola (1, 2, 3) , Pascal Chrétien (2) , Sophie Delprat (4, 1) , Karim Bouzehouane (1) , Olivier Schneegans (2) , Pierre Seneor (1) , Richard Mattana (1) , Sergio Tatay (5) , Bernard Geffroy (6, 7) , Yvan Bonnassieux (7) , Denis Mencaraglia (2) , Frédéric Houzé (2)

1 Laboratoire Albert Fert (ex-UMPhy Unité mixte de physique CNRS/Thales)
2 GeePs - Laboratoire Génie électrique et électronique de Paris
3 Concept Scientific Instruments
4 UPMC - Université Pierre et Marie Curie - Paris 6
5 Molecular Science Institute
6 LICSEN UMR 3685 - Laboratoire Innovation en Chimie des Surfaces et NanoSciences
7 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10 decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes

Mots clés: carbon nanotubes; atomic force microscopy; infrared detectors; self-assembly; optimisation; thin film sensors; electric resistance measurement; photodetectors; monolayers

Domaines: Matériaux

Aymeric Vecchiola, Pascal Chrétien, Sophie Delprat, Karim Bouzehouane, Olivier Schneegans, et al.. Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode. Applied Physics Letters, 2016, 108, pp.243101. ⟨10.1063/1.4953870⟩. ⟨cea-01331971⟩