Dirk König works in the areas of theory and characterization for the disciplines of solid state physics, quantum chemistry, and electronic materials engineering. 
A brief selection of present core areas:
(1) Direct modulation doping of Si-based dielectrics on silicon (Si) to conventional impurity doping of Si; far-reaching consequences for very large scale integration (VLSI) chip design & technology with full cryo-functionality (for peripheral qubit electronics at a few 100 mK, removing thermal limits on number of qubits). Another application are highly passivated and long-term stable carrier-selective contacts to Si solar cells, field effect passivation, etc.
(2) Nanoscopic Electronic Structure Shift Induced by Anions at Surfaces (NESSIAS) effect to provide the energy landscape for filling low nanoscale Si with electrons or holes from external interconnects, eliminiating conventional impurity doping. Used coatings with ultrathin dielectrics are compatible to CMOS-technology, physical structure sizes (gate lengths) down to ca. 3 nm possible. Again, such prospective devices would be fully cryo-able (for qubit peripheral electronics), work at higher speeds (carrier mobilities), using much less energy (lower bias), and strongly reduced heat load.
(3) Analytic nano-metrology of diamond/zinc-blende nanocrystal (NC) shape, and of cross-sections of diamond/zinc-blende/wurtzite nanowires (NWires) shapes down to the individual atom and bond. Mathematic constructs allow for straightforward use in any spectroscopy technique for relating any spectroscopic data to structural parameters, e.g. thermodynamic optimum of NWire cross section during NWire growth. 
A brief selection of past/dormant core areas:
(4) Tuning photoluminescence energies and intensities in Si NCs doped with transition metal atoms on interstitial lattice sites.
(5) Hot carrier non-equilibrium dynamics, optoelectronic conversion principles, materials, energy-selective contacts and structures for prospective hot carrier solar cell prototypes.
(6) Perception, design, construction, and commissioning of optically assisted current-voltage (oa-IV) characterization technique as a means to observe hot carrier populations in the steady-state (vs. time-resolved) domain by optoelectronic probing (photons in -- hot carriers out) vs. indirect carrier tracing methods such as time-resolved photoluminescence (photons in -- photons out).
(7) Quantum structures in Si-based solar cells and energy-selective contacts.
(8) Field effect and chemical passivation of Si/SiO₂ interfaces by fluorine- (F-) deficient Aluminiumtrifluoride (ALF3)