The research of the group of Dr. M. DeKieviet focusses on the structure and dynamics in and at the outermost surface layer of advanced materials. The studies include the characterization of well-ordered thin organic films, with particular emphasis on interplay between the surface structure and the dispersion of the corresponding phonon modes. These investigations are performed using a "traditional" Helium Atom Scattering (HAS) apparatus, equipped with a high resolution Time-of-Flight (ToF) spectrometer (energy transfer ranging from 0.1 –10 meV).
In extension to the study of ordered materials, the group of Dr. M. DeKieviet plans to measure charge transfer processes in disordered organic materials. The charge transfer process in organic electronics is known to be accompanied by electronic and vibronic excitations that follow dissipative decay channels which lie just below the surface. The goal is to identify these decay channels and to systematically investigate them with respect to their charge transfer efficiency.
For this purpose, a second atomic beam using 3He will be installed under grazing incidence on the existing HAS apparatus that makes use of the spin echo principle. The Grazing Incidence Helium Atom Scattering (GIHAS) spectrometer is now under construction at the CAM. Once installed, the GIHAS experiment will be used to measure polaritons and plasmons in organic electronic films that are excited through charge transfer, The 3He beam will provide a spatial resolution that ranges from local atomic structures (10 pm) up to the morphology of larger domains (a few microns). This, in combination with the above mentioned energy resolution, makes the GIHAS experiment the world's first instrument of its kind.