Thermally‐activated post‐growth dewetting of fullerene C60 on mica. Issue 11 (20th October 2015)

• Record Type: Journal Article
• Authors: Bommel, Sebastian; Spranger, Holger; Weber, C.; Kleppmann, N.; Roth, Stephan V.; Klapp, S. H. L.; Kowarik, Stefan
• Is Part Of: Physica status solidi. Volume 9:Issue 11(2015:Nov.)
• Page Start: 646
• Page End: 651
• Publication Date: 2015-10-20
• Subjects: organic semiconductors -- C60 -- mica -- thin films -- X‐ray scattering -- post‐growth dewetting -- mass transport; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201510258
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Understanding and controlling the growth and stability of molecular thin films on solid surfaces is necessary to develop nanomaterials with well‐defined physical properties. As a prominent model system in organic electronics, we investigate the post‐growth dewetting kinetics of the fullerene C60 on mica with real‐time and in situ X‐ray scattering. After layer‐by‐layer growth of C60, we find a thermally‐activated post‐growth dewetting, where the smooth C60 ‐layer breaks up into islands. This clearly shows that growth is kinetically limited before the system moves over an activation barrier into an energetically favored configuration. From the temperature‐dependent dewetting kinetics we find an effective activation barrier of 0.33 eV, which describes both the temperature‐dependent macroscopic changes in the surface morphology and the microscopic processes of inter‐ and intralayer diffusion during dewetting. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) Abstract : Real‐time and in situ X‐ray scattering show that the fullerene C60 performs thermally‐activated post‐growth dewetting on mica, where the smooth closed layers of C60 formed during growth break up into islands during post‐growth relaxation. In their studies, the authors first quantify the thermal stability of the molecular thin film. This forms a fundamental contribution to the understanding of functional molecular materials and their long‐term (morphological) stability.