Summary of Section A
Project area A (materials research, electronic properties and advanced characterization) forms the basis for the development of novel devices. The topics of A include the synthesis as well as the characterization of group III-arsenide and III-nitride nanostructures. GaAs and GaN based nano-materials are presently the commercially most relevant for novel photonic devices and will enable us to address a number of complementary issues. The more advanced GaAs materials system will provide the foundation for the development of a multitude of novel device designs, like ultra-high bit rate VCSELS and nano-lasers. The group III-nitride material systems features large band gaps and huge exciton binding energies, which will be vital in order to realize close to room-temperature single photon emission, polariton lasing as well as deep UV lasers. By comparing the structural, electronic and optical properties of different nano-materials we will also obtain a deeper understanding of the fundamental physics of quantum dots and develop novel growth methods that allow us to control size, shape, composition and areal density of these nanostructures. The main objective is hereby the fabrication of completely integrated, complex device structures including quantum wells and quantum dots for the active areas. Newly developed epitaxial growth processes, like sub-monolayer structures or defined positioning of Stranski-Krastanow grown quantum dots belong to these tasks of research.