The optical and electronic properties of materials based on nanoparticles can often be tuned in a wide range. In principle, these materials offer a way to overcome the limitations of design problems in important and multifaceted applications such as organic solar cells, organic light emitting devices, batteries, fuel cells, and photon detectors. Presently, only a very limited number of commercial products make use of this opportunity. The complex dependency of functionality and size, doping, details of the sintering process, and morphology in combination with the lack of appropriate structural and electronic characterization and simulation tools may cause this discrepancy. By bringing the communities of materials synthesis and x-ray characterization together, this workshop will provide a forum for discussion of the ways synchrotron-based x-ray probes can provide essential information for the rational design of new materials.