title: Revealing surface oxidation on the organic semi-conducting single crystal rubrene with time of flight secondary ion mass spectroscopy.
abstract: To address the question of surface oxidation in organic electronics the chemical composition at the surface of single crystalline rubrene is spatially profiled and analyzed using Time of Flight - Secondary Ion Mass Spectroscopy (ToF-SIMS). It is seen that a uniform oxide (C42H28O) covers the surface while there is an increased concentration of peroxide (C42H28O2) located at crystallographic defects. By analyzing the effects of different primary ions, temperature and sputtering agents the technique of ToF-SIMS is developed as a valuable tool for the study of chemical composition variance both at and below the surface of organic single crystals. The primary ion beams C60(3+) and Bi3(+) are found to be most appropriate for mass spectroscopy and spatial profiling respectively. Depth profiling of the material is successfully undertaken maintaining the molecular integrity to a depth of ~5 μm using an Ar cluster ion source as the sputtering agent.
authors: Department of Electronic and Electrical Engineering, University College London, London, UK. robert.thompson.09@ucl.ac.uk
authors: Robert J
authors: RJ
authors: Thompson
authors: Sarah
authors: S
authors: Fearn
authors: Ke Jie
authors: KJ
authors: Tan
authors: Hans George
authors: HG
authors: Cramer
authors: Christian L
authors: CL
authors: Kloc
authors: Neil J
authors: NJ
authors: Curson
authors: Oleg
authors: O
authors: Mitrofanov
mesh_terms: D008958:Models, Molecular; D009279:Naphthacenes / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D012666:Semiconductors; D018629:Spectrometry, Mass, Secondary Ion; D013499:Surface Properties; D013997:Time Factors
chemical_list: D009279:Naphthacenes; C045049:rubrene