The ordering of organic (carbon-based) molecules into nanostructures drives useful materials properties for applications such as organic light emitting diodes, polymer batteries, and flexible transistor circuits. However, there is a current lack of techniques to measure this ordering. Recently, X-ray scattering techniques involving molecular resonances have shown promise in distinguishing molecules and their orientation. Such a resonance occurs when an atom absorbs an X-ray precisely tuned in energy to excite a core electron into a bound molecular orbital associated with a local bond. Each resonance is bond selective, and the X-ray polarization is, furthermore, sensitive to the orientation of that bond. The objective of this research is to develop methods, models, and analysis techniques that harness these resonant phenomena in X-ray scattering measurements to quantitatively probe ordering of organic molecules within nanostructures. New physical models for polarized resonant X-ray scattering that accurately describe these complex molecular resonances will enable measurements of how molecules assemble, orient and conform at the nanometer scale. The work will test the sensitivity of the technique in terms of both spatial resolution for molecular position and orientation for molecular ordering. This new measurement capability will enable characterization of structure-property relationships that lead to disruptive technologies of printable, stretchable, and biocompatible devices based on organic materials.
