Structure Matters: Combining X-Ray Scattering and Ultraviolet Photoelectron Spectroscopy for Studying Organic Thin Films

In this chapter the relationship between organic film structure and ultraviolet photoelectron spectroscopy (UPS) data is discussed. As a useful method for obtaining detailed structural data we first summarize shortly the advantages of X-ray scattering. Here, of course we cannot include the full body of literature on interface-sensitive X-ray scattering but rather refer to general references. By combining such structural data and electronic information from UPS new insights in the fundamental principles of organic electronics can be obtained. On the basis of single layer and heterostructures we discuss the dependence of the electronic level alignment and the spectral shape of the HOMO band on the structural properties of organic thin films. The crystallinity and therefore also the electronic properties of an organic thin film can be tuned by controlling growth parameters such as the substrate temperature. The examples are drawn from our own work in order to specifically relate to other chapters in this book, which is not intended to imply that there are no others [1–3].