Real-time insight into nanostructure evolution during the rapid formation of ultra-thin gold layers on polymers

• Published in: Nanoscale horizons Vol. 6; no. 2; pp. 132 - 138
• Main Authors: Schwartzkopf, Matthias, Wöhnert, Sven-Jannik, Waclawek, Vivian, Carstens, Niko, Rothkirch, André, Rubeck, Jan, Gensch, Marc, Drewes, Jonas, Polonskyi, Oleksandr, Strunskus, Thomas, Hinz, Alexander M, Schaper, Simon J, Körstgens, Volker, Müller-Buschbaum, Peter, Faupel, Franz, Roth, Stephan V
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.02.2021
• Subjects: Aspect ratio; Data analysis; Deposition; Equilibrium conditions; Evolution; Gold; Light emitting diodes; Motion pictures; Optoelectronics; Photovoltaic cells; Polymer films; Polymers; Polystyrene resins; Thin films; Uncertainty analysis
• ISSN: 2055-6756; 2055-6764; 2055-6764
• DOI: 10.1039/d0nh00538j

Ultra-thin metal layers on polymer thin films attract tremendous research interest for advanced flexible optoelectronic applications, including organic photovoltaics, light emitting diodes and sensors. To realize the large-scale production of such metal-polymer hybrid materials, high rate sputter deposition is of particular interest. Here, we witness the birth of a metal-polymer hybrid material by quantifying in situ with unprecedented time-resolution of 0.5 ms the temporal evolution of interfacial morphology during the rapid formation of ultra-thin gold layers on thin polystyrene films. We monitor average non-equilibrium cluster geometries, transient interface morphologies and the effective near-surface gold diffusion. At 1 s sputter deposition, the polymer matrix has already been enriched with 1% gold and an intermixing layer has formed with a depth of over 3.5 nm. Furthermore, we experimentally observe unexpected changes in aspect ratios of ultra-small gold clusters growing in the vicinity of polymer chains. For the first time, this approach enables four-dimensional insights at atomic scales during the gold growth under non-equilibrium conditions. At the nascence of a metal-polymer hybrid material primarily vertical Au dimers and free adatoms diffuse on and into the polymer matrix revealed in situ by sub-millisecond time-resolved surface-sensitive X-ray scattering (GISAXS).