The Commonn Research Service (CRS) brings together support activities for CRHEA's research teams. It includes the technology platform (Technology platform), optical characterization and structural characterization (DRX, AFM, SEM, TEM). The various techniques of the service are used by the researchers of the laboratory, the SCR personnel intervening for the most advanced measurements. These tools are also accessible to laboratories and external companies. Research activities of its own are developed within the SCR in relation to topics internal or external to the laboratory.
The Common Research Service works mainly on CRHEA epitaxial layers (III element nitride, ZnO and its alloys, SiC, graphene). The activity of Technology platform consists in the preparation of samples for epitaxy, and the realization and optimization of micro and optoelectronic devices. The optical characterizations of the SCR cover a wide spectral range, from ultraviolet to infrared. These devices allow a rapid evaluation of materials as well as the development of more complete analyzes to update properties or mechanisms still little known within the class of materials developed in the laboratory. X-ray diffraction (XRD) makes it possible to determine the crystalline quality of the epitaxial layers as well as their state of stress, the composition of the alloys produced as well as their thickness, and the compositions / thicknesses of the multilayers. These thicknesses can also be determined by scanning electron microcopy (SEM), after cleavage of the sample. This technique also allows chemical contrast imaging. Atomic force microscopy (AFM) shows the atomic steps and through-dislocations of epitaxial layers, allows to measure the surface roughness of layers and to evaluate the size of quantum dots. The latter are also widely studied in Transmission Electron Microscopy (TEM), a technique that allows precise measurement of the thickness, composition and morphology of hetero-structures with micrometer to nanometer sizes, as well as the analysis of structural defects (measurement of densities, determination of their nature).
The expertise center in characterization presents the technical description of the structural and optical characterization tools used and maintained by SCR.
- For any question about the SCR team: Marc Portail