III-Nitrides for applications in the next generation of wireless communication, sensing, and power infrastructures. The research focuses on optimization of epitaxial design and properties of GaN and AlGaN device structures on SiC, GaN and AlN substrates by hot-wall MOVPE. The activity covers growth of the device structures with the main aim to minimize defect densities (dislocations and background impurities), and the design of the epi-stack targeting different functionalities, e.g. power amplification, noise, and flicker-noise, switch losses, device design, etc.
Terahertz ellipsometry and optical Hall effect. We have developed unique THz ellipsometry and magneto-ellipsometry (optical Hall effect) instrumentation at the Terahertz Materials Analysis Center. These novel techniques makes it possible to explore electronic, transport and magnetic properties and phenomena in e.g, semiconductors, nanomaterials, organic materials, which cannot be assessed by other means. Current research efforts include application of THz to FIR ellipsometry to study 2DEG in transistor and quantum structures, 2D materials, conductive polymers, proteins and biomaterials.
Ultra-wide bandgap semiconductors. Main focus is put on β-Ga2O3 for applications in high-power electronic devices with substantial efficiency gain in e.g., generation and transmission of electric power, electrification of vehicles and motor drivers. Current research efforts include development of MOVPE of β-Ga2O3 and profound understanding of phonon, free charge carrier and electronic properties in relation to microstructure of thin films and device heterstructures.
2D materials. Current research activities include using THz ellipsometry to study, understand and optimize the transport, electronic and structural properties of e.g., epitaxial graphene grown on SiC, MAXens, and BN.