title: Local surface potential of π-conjugated nanostructures by Kelvin probe force microscopy: effect of the sampling depth.
abstract: Kelvin probe force microscopy (KPFM) is usually applied to map the local surface potential of nanostructured materials at surfaces and interfaces. KPFM is commonly defined as a 'surface technique', even if this assumption is not fully justified. However, a quantification of the surface sensitivity of this technique is crucial to explore electrical properties at the nanoscale. Here a versatile 3D model is presented which provides a quantitative explanation of KPFM results, taking into account the vertical structure of the sample. The model is tested on nanostructured films obtained from two relevant semiconducting systems for field-effect transistor and solar cell applications showing different interfacial properties, i.e., poly(3-hexylthiophene) (P3HT) and perylene-bis-dicarboximide (PDI). These findings are especially important since they enable quantitative determination of the local surface potential of conjugated nanostructures, and thereby pave the way towards optimization of the electronic properties of nanoscale architectures for organic electronic applications.
authors.affiliation: Instituto per la Sintesi Organica e la Fotoreattività-Consiglio, Nazionale delle Ricerche, Via Gobetti 101, I-40129 Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Liscio
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Palermo
authors.forename: Oliver
authors.initials: O
authors.lastname: Fenwick
authors.forename: Slawomir
authors.initials: S
authors.lastname: Braun
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Mats
authors.initials: M
authors.lastname: Fahlman
authors.forename: Franco
authors.initials: F
authors.lastname: Cacialli
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorí
mesh_terms: D007094:Imides / Q000737:chemistry; D018625:Microscopy, Atomic Force / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D010569:Perylene / Q000031:analogs & derivatives / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D013499:Surface Properties
chemical_list: D007094:Imides; C510697:perylene bisimide; D011092:Polyethylene Glycols; D010569:Perylene