AMADEus Seminar - Dr. Guiseppe Portale - Thursday 8 march 2018 - 11:00 am ENSCBP (Bât A Amphi 3)

Abstract

Solution processing is greatly appreciated in many device manufacturing fields such as organic photovoltaics and block-copolymer nanolithography due to its ease, flexibility, and capability for high throughput device fabrication. Independent of the technological application, control over the structure and feature size which characterize the formed morphology is required. To control the structure it is crucial to understand the mechanisms that govern the morphology formation process. Spin coating is one of the simplest method to produce thin supported organic films in the laboratory. However, the mechanism of structural evolution during spin coating is often unknown as in-situ structural studies during spin coating are quite challenging and have been rarely achieved so far, especially in organic systems.

In order to tackle this challenge, we have designed a multi technique approach to perform, in-situ and in real time, simultaneous gracing angle small angle X-ray scattering (GISAXS), laser interferometry and laser scattering measurements during spin coating. During this talk, I will show you some recent results on the mechanism of phase separation and self-assembly occurring during spin coating in polymer blends. By combining laser and X-ray results, a full view of the structuring process occurring during ultrafast drying of a polymer/small organic molecule blend (namely PS and PCBM) could be obtained. Our approach is not only limited to polymer blends, but it can be applied to other interesting systems such as block-copolymers, polymer-nanoparticle systems and even inorganic systems.